100% Noob. Need help overclocking older CPU

First of all, my rig. Economy build (most parts) from 2010. ECS IC780M-A2, AMD Phenom II X3 740 Black Edition, ARCTIC Alpine 64 Pro Rev. 2 CPU Cooler, 8GB (2 x 4GB) DDR3 1333, Sunbeam Transformer ATX Full Tower Case. (more parts of course, but I think that's all you'd need to see)

So, I'm trying to run Dark Souls 3 (I do have a better PC but I'm trying to co-op with this old one) and it's not working well. Upgrading the PC isn't really an option so I thought I'd try overclocking the CPU (and maybe later the GPU).

I'm able to access the "intelligent" bios screen that lets me control the voltage and frequency but I don't know WTF I'm doing so I backed out of there without making any changes. This is the screen I get, and seem to be the only options I have. I don't know where to start here, what settings so adjust, how to check stability etc. Unfortunately my motherboard doesn't have the option to unlock the 4th core on my CPU to see if it's stable so I'll just have to work with what I've got.

Help me, please? I don't want to play Dark Souls 3 in 800x400 on lowest settings and still have frame rate issues....