An FX-6300, 6350, 8320 or 8350 are probably the CPUs you want to pick from for that motherboard. This is a pretty old platform though. You'd be a lot better off getting the GTX 1060 and any Ryzen 5 or 7, plus a motherboard and memory, than having to buy a CPU for that motherboard.
But, that all costs money, so I understand if that's not possible. Do you currently have memory (RAM) to use with this system and if so what are the model numbers of all modules or the memory kit?
What is the EXACT model number of your power supply?
If ALL you have right now is the motherboard, and you have to get everything else, then you'd be wise to simply sell that board to somebody who NEEDS an AM3+ motherboard, and get an AM4 socket B350, B450, X370 or X470 motherboard along with some DDR4 and a Ryzen CPU.