try
Take a trial lesson or even a few lessons at your local airfield and see how you get on. No need to be a rocket scientist and if you got in to ATC then you are more than likely going to be just fine.
If you do want to proceed more seriously then get the medical done early on. if you are thinking of commercial flying then do the Class 1 (or equivalent) right at the start so if you fail it you are only dissappointed and not dissappointed and broke !!