My monitor cannot get a signal

Hello, I recently have discovered a problem with my monitor and/or possibly with my computer.

This week I have completed my first PC build and was able to install windows, run the BIOS and do everything a normal computer could do just fine, until Wednesday. I was using my computer and then had to go to an appointment for two hours, so I turned everything off, left and came back only to realize my computer cannot find a signal, even though it worked two hours ago. I have tried so many things, such as rearranging ram, unplugging the power cord for 30 secs and plugging it back in, unplugging all wires and plugging them back in again, checked for loose pins, and found absolutely nothing. I've even tried connecting to my router with an ethernet cable, and it did not change a single thing. What really pisses me off though is I'm able to connect to the wifi with a different computer (the one I'm using to write this). I was hoping it was just a temporary issue and it would be back to normal the next day, just like cars sometimes don't work then an hour later they're fine, but I was wrong. It has been two days and nothing has happened and I'm not able to connect to wifi/find a signal. I'm starting to worry if I fried my hardware. I do not know if this is a pc to monitor issue or a pc/monitor to wifi issue. If anybody knows of a solution it would be greatly appreciative if you could help me out. Thank you to anybody that replies, I hope we can solve this over the weekend <3.

Sincerely,
Jason

EDIT: Just took out mobo battery for 10 minutes and put it back, still have the issue.