The piano is a wonderful musical instrument. The idea of learning to play for personal gratification or to entertain others can be exciting and challenging.
Before investing money in keyboards or music, take the time to consider whether you have the time and the discipline to practice your instrument. Even gifted musicians spend hours at their pianos maintaining their skills and learning new material. Though you do not have to spend hours every day practicing, you will need to devote time for learning. Practicing can be tedious, with lots of repetition. If this does not appeal to you, save your time and money for other things.
Decide what kind of music you want to play, and how you want to learn it. Do you want to learn classical pieces by Beethoven and Mozart or do you want to play in a rock band? Do you want to learn to read music, or do you think you can play by ear? Asking and answering all of these questions can help you find the right teacher or books so you can learn to play the piano the way you want.
You do not need a full-sized piano when you first begin learning to play. There are inexpensive electric keyboards available which do not take up much room, in case you live in a small apartment. Headphones will allow you to practice without disturbing others.
Once you decide what type of music you want to play, you must choose how you want to learn. There are free piano lessons available on the internet. Be aware that though some internet piano lessons and sheet music might be free, they may not offer everything you need to learn the basics. There are also courses that let you learn to play by ear; if you are musically inclined, this might be great for you. If you are going to learn with a piano teacher, pick one who is able to both teach the basics and, when you have advanced to the point where you can begin to narrow your focus, will teach you how to play the style of music you love.