For bios settings, you need to set PCIe Link Speed, Disable CSM Support, and usually need to enable Above 4G Decoding.
This is an ancient motherboard, there are no such settings in this BIOS. Above 4G Decoding
I used similar motherboards for mining because I kept them after repairing or upgrading old personal computers.
For mining you need 2 PCI-E x1 slots, but I don't know how this motherboard will work with new video cards.
I used the PX470 on similar motherboards.
First connect 1 video card, if everything is ok, then the second one.
These motherboards are old and unreliable, they broke in less than 1 year.