Will the starter motor crank? The engine isnt froze up? If the starter wont crank, can you turn the crank by hand? Check starter wiring, any testing at the starter make sure tranny is in park or neutral and the parking brake is set.

about a month ago had to change the battery cuz it was dead so i think it might be dead again which means the alternator is prob bad

If you have a digital multimeter we can help you check the battery and charging system. You very well could be on the right track?

Battery was tested and is good. took starter out and had it tested, replaced the starter, and all i get is a single click noise when i try to start it. any ideas?

Can you turn the crank by hand, either at the crank shaft pulley or flywheel? If not the engine is froze up. If the engine is froze up, chasing wiring circuits won't help.

You can check the fuses in the wiring diagram for voltage. You can check voltage circuits at starter, any testing, make sure tranny is in park or neutral and the parking brake is set. Any applicable trouble codes/ security system? What about the neutral switch/transmission range sensor?

Unless you can personally do some testing on the wiring circuits, I dont know what else to tell you.