you are going to waste money on a car like that. yes, you can do an auto to manual swap. but it is expensive... you would need to get all of the parts from a similar manual car. pedals, clutch master and slave cylinders, clutch line, entire shift assembly, different computer, different gauge pack to get rid of the shift lights from the auto, also have to replace the center console the shifter comes through... and all this for a car with a value of lets say $5k being overly generous? wait, since it has no power anything and no vtec it is proy just a DX or something so the value is even lower.
if you really insist on doing this, and want to swap the engine or whatever, make sure you get a full swap that has motor, tranny, computer, shift linkage, and all the rest of that good stuff. that will at least give you a bit of a start on the parts you need to do the auto to manual conversion
I kind of get the feeling there is BS involved in this post. You say you and your friend are just 16 and somehow you saved up the money to buy a 2002 Subaru WRX. (I am aware you say you have been saving since you were 13. What are you in the damn mob? When I was 13 I wanted candy and toys, I didn't dream of having a WRX that didn't exist yet) But then what is this about the '99 Accord? Who's name are you typing under? I hope you aren't talkin some BS on here. People don't like that very much around here. Goodluck with the project.