To keep you from wasting your time, I'll give you the short version. You CANNOT mine STEEM anymore. The guys who designed it decided to take away mining ability for STEEM after hard fork 17.

Most of mining software tend to gear toward open source (free software) so if you can install Ubuntu LTS, you should be able to download miner for majority of coins.

If you want to make a profit (after paying electricity), you want a GPU mining rig (one mother board connects to 4-6 GPUS at the same time), coins like Ethereum depend solely on GPU for mining. Coins like XMR require both good GPU and decent amount of memory/RAM.

Since you're not really savvy at all this computer bs, I would suggest looking into a relatively respectable cloud mining service and sink your money there. Beware that the initial cost of buying that service/hardware is expensive and you'll only see profit after 3 months or so. That's how long it takes to break even.