Here are a few suggestions to make the most of your practice time.
I recommend that my students spend time on each of the three categories: Technique, Repertoire, Creativity. The amount of time you devote to each section will depend on your goals. I recommend always doing a short warm-up (scales, patterns, arpeggios, cadences). It is practical to always choose the scales and patterns of the piece you are working on. Other beneficial activities related to the practice of technique and theory that you could include in your daily practice routine: sight reading, playing a song by ear, finding the chords to a known song by ear.
The secret of acquiring a good technique is to approach your practice mindfully and with 100% concentration. Make sure you don't rush through this part of your daily practice. It is important to be aware of your tone quality, to keep a steady, slow rhythm, and to play evenly. To avoid bad habits and wrong movements, it is highly recommended to be guided by a private teacher. Why is it so important to practice scales and arpeggios? Hopefully, it's not because you want to be the most agile and fastest piano player - while it's true that your speed will improve with practice, you should do the technical exercises primarily to improve your control, coordination, and understanding of the topography of your keyboard. We practice scales and arpeggios because they can be found in all music (as small elements and fragments), and getting familiar with all the keys will help you immensely when learning a new piece. If you practice chords and arpeggios, you will be able to recognize them in the repertoire and immediately use the most appropriate fingering.
I offer a free course on practicing chords and scales (this course is in preparation) where you can practice along with the video.
After you have mastered playing the scales and arpeggios at a slow tempo, practice with the metronome. First you need to master them in two octaves, then do them over four octaves. When you are ready to expand your practice of major and minor scales, start playing them in thirds and sixths. It may seem tedious to work on your technique, but the benefits will certainly outweigh the 5-10 minutes a day you devote to your scales. If you stick with it and incorporate it into your daily practice, you will improve your playing not only on the level of performing the repertoire, but also your sight-reading skills as you will begin to recognize the elements in the music you are playing. It will allow you to think strategically in any key, thus easing your spontaneous music-making and helping you develop your own expression.
Practice a selected piece from the repertoire section. When looking for repertoire for my students, I try to find pieces that have different characteristics - at least one for their own enjoyment, then there are didactic compositions that address a specific technical problem, such as articulation, dynamics, or finger technique, and I also try to cover compositions from all periods of classical music.
You should never practice a piece from beginning to end. Mindless repetition will hinder your progress and productivity, which will ultimately have a negative effect on your motivation. I suggest that you do not always start practicing at the beginning.
Divide the song into meaningful parts. Pay attention to the melody - it is often possible to divide it into 2-bar phrases, then further into 4-bar and 8-bar segments. Mark each segment with a number and choose the most difficult segment to begin the practice lesson. Remember that you are your own mentor when practicing and make sure that you do not waste your precious practice time on what you already know how to do, but focus on your weaknesses.
To this end, it is very useful to record your playing. When you identify which parts are the most difficult, mark them and start practicing those parts the next day. But do not leave it at that; like a detective, try to figure out exactly where the difficulty lies. Are you using an awkward fingering, did you learn a wrong note from the beginning, is your finger not strong enough, or you cannot hit that jump in time? If you don't have a teacher to help you with your difficult passages, analyze the exact moment you make a mistake and try to find a solution by playing that measure very slowly, paying attention to the progression from one note to another.
I also suggest that you make friends with your metronome and practice each section at a slower tempo until you stop making mistakes. Then play the piece from beginning to end, noting whether you speed up or slow down in the different sections of the piece. Once you have learned the composition, start memorizing it. You will improve your performance immensely if you play it by heart. If you do not read the notes, you will be more attentive to the interpretation and the small details that give life to the music you are playing. Enjoy your performance, but watch out for tension or excessive movement while you play.
I encourage my students to make a list of popular songs they would like to learn. It's easy to forget, so maybe make a playlist of new pieces you'll learn in the future. However, I would advise you to first try to find your own interpretation of a song you like. If you listen to too many covers on YouTube, it might interfere with your own ideas. Try to find your own unique interpretation of the well-known song, and only then plunge into the sea of other artists' interpretations.
Once you have decided on a song, I suggest that you first learn to sing it (or hum it if there are no lyrics). Then try playing it by ear. I do not think playing by notes is at all better than playing by ear. In fact, it's more natural to learn by ear first. Take your time and go slowly phrase by phrase, skipping over sections that are too difficult, and try to find as many notes as you can by ear. Playing by ear is a slow process, but it is very beneficial because it helps you make the connection between your inner hearing and playing the same notes on the piano. A good exercise to develop playing by ear is to always sing while you play the piano - when you practice your pieces, sing while you play the melody, and also while you practice your left hand if the accompaniment allows it. My advice is to set a goal of learning at least one new song by ear each month. I will prepare a list of suggestions depending on the level of difficulty.
If you can play the melody of the new song with ease, try to find the chords by ear as well. For a beginner, this can be quite difficult, so do not expect to get it right on your first few tries. But with practice - I assure you, it gets easier and easier, and the confidence you get when you can hear and recognize the chords on the piano is amazing.
For me, improvisation is by far the most beautiful way to make music. All of my students improvise without exception. We always make time for short improvisational exercises related to the pieces they are playing, and we invent our own improvisational introductions by changing the basic elements of the chosen composition a bit. This is a great way to learn the language of music and understand how each musical element (melody, rhythm, harmony, texture) affects the others and the whole piece. Since I specialize in teaching improvisation, I would like to invite you to take my free course on improvisation. If you have never improvised before, it will be a step-by-step introduction to letting go and exploring the expressive possibilities of your piano. The emphasis is not on music theory, but on a variety of ways to discover the joy of spontaneous music making.