If there is one bit of advice I would say it is to do exams. I learnt the viola when I was little and did exams, which are much more nerve-wracking than a performance to a crowd. I recently did my grade 5 Trinity Rock & Pop Drums. It focuses your practice. Plus there will come a time in your life when you may need a qualification to prove you can play the drums and grades is all we have!

If you want to do it just do it. Book a lesson and have a crack at it the longer you wait the more you'll regret not learning sooner later in life.