First time build: boot, no errors? What?

[standardeviation]

From having never owned a PC (mac user through youth) I find it strange that I was seemingly able to boot my custom build first time without any errors. Boot screen displays, and all fans/lights working properly minus one RGB ram led.

*This is not meant to be a pat on my own back*

What should I do before booting OS in drive? Also is it a concern that only one RAM stick is lit? PCPartPicker shows compatibility, however, via the supported RAM list on ASRock's website for the B350 mobo the RAM is not on the list. Is this a problem? If I was able to get the boot screen is it possible the RAM is working as it should?

Also when do I do BIOS? Before or after booting OS?

Build:

CPU: AMD - Ryzen 5 1600 3.2GHz 6-Core Processor ($197.43 @ OutletPC)
Motherboard: ASRock - AB350 Pro4 ATX AM4 Motherboard ($73.98 @ Newegg)
Memory: GeIL - EVO X 16GB (2 x 8GB) DDR4-3000 Memory ($135.88 @ OutletPC)
Storage: Samsung - 850 EVO-Series 250GB 2.5" Solid State Drive ($89.99 @ B&H)
Storage: Seagate - BarraCuda 1TB 3.5" 7200RPM Internal Hard Drive ($44.38 @ OutletPC)
Video Card: Gigabyte - GeForce GTX 1080 8GB G1 Gaming Video Card ($518.99 @ SuperBiiz)
Case: Rosewill - CULLINAN ATX Mid Tower Case ($94.99 @ Amazon)
Power Supply: Corsair - RMx 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($59.99 @ Newegg)
Total: $1215.63

 

[Curlev]

You can go into BIOS and check how much ram the PC detects. Maybe it is just the LED on the stick that are broken? Usually the Motherboard have light codes for bad ram.