I can help with CPU mining. I can help for Windows. The fact you have 8 GB ram tells that you have x64 OS, which is important to have.
Do you have a wallet installed? If not, go to
https://bitcointalk.org/index.php?topic=583449.0 and get a wallet.
Or you can find a pool that mines directly to exchange, but most pools don't do that afaik and it's not advised.
A pretty good miner is here
https://bitcointalk.org/index.php?topic=1326803.0Download the binaries, not the source code.Open the readme, see which miner exe is OK for your system. It may be cpuminer-btver1.exe and if it doesn't work you can try the other ones too.
start /low the_correct_exefilename.exe -a cryptonight -o stratum+tcp://pool.minexmr.com:4444 -u your_wallet_address -p x
You can change the pool and port too if you want.