Sitting either too close or too far away from the piano can ruin your technique and make it much more difficult to play. Likewise, poor posture can limit your movement and limit your ability to play harder pieces without discomfort.  Sit on the edge of the piano bench and move it either forward or backward until your elbows are slightly in front of your shoulders when your hands are on the keys. If you have a curved spine or related disability, you may not be able to achieve the same positioning as an able-bodied person without pain. Adapt the technique as best as you can and focus on minimizing discomfort while maximizing your ability to play the instrument.  Make sure your wrists extend straight from your arms, rather than bending. Bending your wrists can cause muscle tension and strain that could eventually lead to overuse injuries. pieces early so you can focus on technique. If you memorize a piano piece at the same time you're learning it, you won't have to worry about reading the sheet music or thinking about the notes. Instead, you can focus on your body position and the way you play the notes.  After you've memorized a piece, you can start to really feel the music. Even without the sheet music, you'll develop the intuitive ability to know when to pedal, when to play loudly or softly, and how to emphasize particular phrases in the music. You can also work on your tempo and rhythm more easily when you're not having to think about which notes to play. Even the most experienced professional piano players have weaknesses. Instead of trying to work around them, find ways to challenge them and improve those areas until they are no longer weaknesses that limit you.   For example, if your left hand is weaker or slower compared to your right, do strengthening and dexterity exercises that focus on your left hand. Bring your left hand up to the same level as your right and then you can continue strengthening both hands. If particular movements give you the most trouble, practice them over and over until the movement becomes second nature. Choose pieces that challenge your weaknesses in particular and encourage you to step up, rather than avoiding pieces that rely heavily on the skills you need to work on. While you may find it difficult at first, these pieces will help you improve your playing skills. Many beginners play the piano with flat fingers, which can hinder your ability to play more complex pieces later on. Once you've developed this habit, it can be hard to get rid of. However, if you practice curling your fingers on a regular basis when you aren't at the piano, your fingers will learn to fall into this position naturally.  Hold a ball in the palm of your hand and curl your fingers around it to mimic the shape you should be making when you play the piano. You can also squeeze a stress ball, which helps strengthen all the tiny muscles in your hands and fingers. If you regularly type, try holding your hand in the correct piano-playing position while you're typing. This will help get your hands in the habit of making that shape. Exercises that condition the muscles in your hands and forearms will improve your piano playing skills, particularly your ability to move your fingers more quickly. Many piano players start with Hanon exercises to build dexterity and improve technique.  To start, you can download 20 different Hanon exercises for free at https://www.hanon-online.com/. However, keep in mind that while Hanon exercises can be great for beginners, they do have limitations and won't help you acquire many piano techniques that can improve your playing. Exercises away from the piano that are designed to strengthen your hands and forearms will also help your piano playing. For example, you might look for hand and forearm exercises designed for rock climbers. The piano is an instrument best-suited to long fingers and large hands. However, having a less-than-ideal hand size or shape does not mean that you can't become adept at the instrument. There are plenty of different fingering patterns you can use.

Summary:
Check the position of your piano bench. Memorize Identify your technical weaknesses. Work on your hand shape while away from the piano. Use hand and finger exercises to build muscle and dexterity.