Need tips for first time mining !

Hello everyone!
I am going to mine using 20 PC's they are actually gaming PC's for a gaming network.
I am wondering which are the best programs to mine with? How to calculate the electricity usage. Also will I be using more actual electricity than I already use since the PC's are active for gaming? I am made some calculations and I am aiming to mine Ethereum, any other suggestions?
I need help in calculating the income of each PC, and whatever tips/advices that are possible, thank you in advance!

PC's Specs: 3070 TUF, intel 10700 on a b460 TUF motherboard, 16GB Ram 3200 cl 16 runs at 2933, ssd 500gb + 1tb hdd, 650w psu seasonic gold! Only using fan cooling