dont bother with custom bios.
smOS allows settings similar to msi afterburner that will save you money.
you are new get used to mining first.
If you expand try using the same exact card and purchasing a bios from Eliovp
every card needs a different bios.
I don't both with custom bios I use smOS here are my settings for first card.
I save due to the 1 vs 5 or 6 or 7 in the power stage
I set the core at 1100 vs 1242
I left memory stock at 1650
these two cards are ms rx 470 red led gaming model
all my rigs various cards all can do powerstage 1 which saves money
this is all you need to know for now