Ok recap time,

-Pulled it all apart
-Noticed one of the two ATX 4-pin connectors (for the CPU) was loose.
-I can get it to turn on and remain on with the following connected gpu/ram/case fans/basically everything but the cpu. But it does not display anything on screen.
-When I do connect the power to the cpu it flashes/spins fans for a split second and turns off. Even when I unplug all but the cpu.

Later on when sillyface goose get off her computer I can going to test my ram/cpu/psu in her system and her psu in mine. This should narrow it down to whether its my psu/mb/cpu. Hoping its the mb to be honest, she threw away my cpu box so I can send it back -_-;;

Why I think its the mb, if one of the 4-pin connectors was loose this could short the connection on the mb? But at the same time it could short the wire on the psu or even the cpu? lol I hate myself for rushing this build!

take out out cpu and re set it or rebuild the comp using your components so that you know everything is firmly in place and hasn't become disconnected since the original problem since sometimes you can cause something to come loose while fixing the original problem.

I have, just need to test the psu/cpu in another system so I can narrow it down to which thing.