Amazonia,
I'd recommend that you spend a bit of time in you local library. There have been many books written on the subject of basic bike designs, the parts and their relationships. Some have large color illustrations. You can find modern ones in your local large chain bookstore, too.

Although we're in a high tech age, sometimes books are still best for some, but maybe not for you. If your dyslexia doesn't allow you to concentrate and read for any length of time comfortably, then maybe you can locate a bike coop nearby. The volunteers there may be able and willing to discuss the differences and show you examples. Using the question-answer format, you might learn what you need.

Good luck.

PG