Help needed, first build

[Nemo03]

This is my first pc build, I’m having issues with the first boot up. 
Specs: 
MB- b450 aorus m 
Gpu- gigabyte Radeon rx580 8gb
Cpu- Ryzen 5 2600 stock cooler
Ram- t force ddr4 2x8
Psu- evga 600br 
Ssd- wd blue 500gb
Hdd- wd blue 1tb

I’ve done a ton of research beforehand and it’s killing me that i can’t figure out what I’ve done wrong. It could be something stupid but I need some help. 
I hooked everything up and when I went to boot up nothing happened, power is all connected. I disconnected the power led plug and the vga light came on, I tried to boot again and power came on for a second and shut down. Since I haven’t been able to get any kind of boot or display. The vga light goes off whenever the power led is in though. 
I’ve tried disconnecting and reconnecting the gpu, changing the pcie plug but I can’t get anything. 
Any insight would be greatly appreciated. (Go easy on me I’m still learning)

[SpookyCitrus]

Is the computer plugged in with the PSU switch ON while you're doing all of this? If the VGA light is on that means there is an issue with the graphics card. Was it bought new or tested before it was purchased if it was bought used?

[Nemo03]

Yes everything is brand new, I checked all the power connections and the front panel  connections too and the diagram. Any idea on what could cause the vga light to come on? Or see if there is an issue with the gpu?