You must have a piano (or very nice keyboard) as you will need to practice a lot...like 6-7 times a week.

Piano starts out with very very basic stuff. It may seem boring and very monotonous, but it's essential to learning more advanced stuff. Be very patient while learning, the process can take a lot of hard work with little results at times.

A real piano can be very expensive, as can a good full-size keyboard. If you find yourself short of funds, you can see if someone you know has a piano that you could use for practicing. Also check your school to see if they have a music department/room with a piano you could use for practicing during the day.