Daily practice is essential
Practising is essential if you wish to become a proficient pianist. Attending piano lessons plays certainly a large role in your piano education but it is not enough for you to make good progress. Lessons are offered for you to benefit from a wonderful guidance and structure, but your progress will principally take place during your personal practice sessions.
If you wish to make your dream of becoming a proficient pianist become true, you must discipline yourself and dedicate at least 20 minutes a day to your piano playing, to start with. The amount of time spent at the piano will then increase at a more advanced level.