First of all it makes a big difference what kind of bike or trike you buy. Then of course, I for one recommend a helmet, some sort of a pack to carry tubes and tools. If a tadpole trike you will need clip in pedals. Other wise for a time platform pedals will be fine. Then when it comes to clothes, if it is a diamond frame bike, you may want padded shorts to protect you from the bike. How ever if you chose a recumbent, you can pretty much wear anything you want. As a bent rider I wear t-shirts, and $15 rugby shorts.