So I basically tried to make a gaming pc, first one. And I encountered a big problem. I thought I had everything set up and connected (with the disappointment that my Gigabyte Z370 Ultra Gaming didn’t support RGB) but when I went to turn it on for a final test, the motherboard flickered a little of the led it has and just did nothing at all. I pressed the power button then the fans came on and a red light came on on the motherboard. But it continuously turned off and on by itself within the span of like 10 seconds each one. I’m confused really. Did I hook something up wrong or is something bad?
Specs
AORUS Ultra Gaming mobo
Coolermaster 5 lite RGB case
Intel i3 8100 core processor and fan
EVGA 500W power supply
No ram installed yet
MSI HD 6450 “Graphics card”

--> No ram installed yet

Found your problem.

It's likely the BIOS prevents boot/access without RAM installed (otherwise, what's the point, right?)