I have seen some posts saying that my mobo will be automatically compatible with 3000 series cards out of the box and some that say it won’t. I don’t have a older 2000 CPU to put in so I could update it and I am 95% percent sure that I don’t have a BIOS flash port either. I don’t know where to look in my mother board that it will say it supports 3000 series CPU’s.
Yes, that ASRock motherboard supports the Ryzen 5 3600 Procesor: https://www.asrock.com/mb/AMD/B450M-HDV%20R4.0/#CPU
You need BIOS Version P2.30 installed for that processor to be recognized and boot up your PC.
BIOS Version P2.30 came out on 05/13/2019. More than a year ago. If you purchased your Motherboard after June 2019 it is an excellent chance you already have BIOS Version 2.30 or newer installed. So it should work out of the box.
According to ASRock, the BIOS Version that is installed on your motherboard is printed on the Motherboard's BIOS Chips: