Just needed to be pointed in the right direction, plz help

Hi everyone. THis is my first post here, and I just had some questions, and Id appreciate any replies.

Im pretty much decided on getting a used Civic sedan, and its not going to be anything older than a 1999 model.

Anyways, Id really like to get into the world of Civic mods. I really have no experience doing mods, and no real knowledge of mods that can be performed on a Civic.

I know tho that I probably wont do any engine mods, Id just like to do some exterior ones, like add a spoiler, change the wheels, change the lights for sure.

So, my questions ..... say for example I wanna change the lights. I just go to a mod store and pick up any lights that I like, or do I have to make sure that they fit the Civic, etc ??? Like, where can I do my research on those sort of things before I walk into the store ? The same goes for wheels, and rims .... Also, can I install lights by myself, or does it have to be given to a garage ??

Basically Im a newbie, and Id just like to know what I can do, what I need to look for before I make any mods .... and also if anyone has any good links on intros to Civic mods, I would really appreciate those as well.

Thanks a lot to everyone who (seriously) replies.