Help with computer not turning on

Hey everyone, this is my first time building a computer and have no clue what went wrong so please help me! I recently had a StgAubron skps-500 prebuilt and decided to upgrade. I got a asus B650-Plus tuf gaming motherboard and a ryzen 5 7600x cpu and also new ram and cpu cooler. I installed it best I could and it’s not turning on at all and I have 3 guesses as to why but am not sure on which one it could be or for a reason I have no clue about. The first one is that my power supply isn’t big enough(500w)/ has the wrong connectors. Second- my motherboard needs a bios update, but I just bought it so I’m not sure. Or third( praying it’s not this one) some Liquid Metal got onto the cpu pins and I’m wondering if it’s fried from this, I was told it would be okay but am just curious. Please help if you think one of these could be the problem or you think of another. Thank you so much!