hello I have a 2019 f150 super crewcab xlt or xl, anyway I want to get some subs for my truck but I don't know if I need to wire it a different way due to it being a stock head unit or if the head unit can take the power of the amp

 

You'll need a LOC or you can use the CK11 harness. Search the audio section. Also there are some vendors around here that can hook you up with a custom made harness.

 

whats a LOC, so i can just get an adapter and everything should be fine?

 

Line out converter. Gives you RCA outputs to connect signal to an amp. You can also use speaker level inputs on some amps. Grab signal from the front channels. Check the audio section for more information.

https://www.f150forum.com/f30/

 

if I were to get a sub with 500 rms 800peak and I have and amp that does 250 rms 1000peak will that affect anything other than underpower