Here is a tutorial on how to set up bitcoin core to be a full node: https://academy.aax.com/en/a-step-by-step-guide-to-setting-up-a-full-node-on-the-bitcoin-network/ . This helps the network a lot. Also you can think about becoming a lightning channel to even earn some Bitcoin without the need of wasting large amounts of power.

I already run the full node, I just wanted to know if I can mine too. I will search about lightning channel. Ty.

and I would like to mine,too (not for profit, just to help bitcoin network).

Since you don't have specialized hardware (ASIC), don't do it. I'd recommend to check Non-specialized hardware comparison and Mining hardware comparison to see the vast difference.

I found somewhere on internet that the command for mining is setgenerate true (1), but it doesn't work.

It's likely you found outdated article, setgenerate command removed on Bitcoin Core 0.13.0.

Too technical for me to understand the difference, thank you for your info!