wiring problems 74 valiant

i know very little about wiring but im going to learn somehow. should i just go for a painless harness? the fuse block looks pretty rusty on the prongs i dont know if i wanna save this rats nest under the dash i feel if im going to do this i might as well do it right. my problem is i dont live ina house so i dont have a garage maybe i can rent one? or maybe a storage? i dont know i'll figure something out.