Before you spend a penny (excuse the pun), download the medical standards required for a Class 1. (aka JAR FCL-3). I think the CAA site may have it or something similar. If you can't, visit your doctor and get tested for diabetes, colour blindness, visual acuity and deafness.
The vision standard is reasonably high, glasses aren't a no go but how strong they are is. (5 dioptres I think?)
WRT applications etc, visit GAPAN and have a look there. They do aptitude testing to see how you'd go. Well worth it.
Other testing, have a look online for "COMPASS" etc.