Mining mainnet with a running node


I follow this tutorial here to run a node
what do I need to do to be mining now?
Is there an additional command after i started the node?


Don’t mine on node, you need to connect to pool, solo mining is useless now.
Follow that


Why is it useless? i really don’t understand


There are two things:
How many graphs you can make per second
How many solutions you can make per second

Usually a fast CPU makes 1 graph every 2 seconds
Usually a fast GPU (1080ti for reference) can make 6.5 graphs per second with an optimized miner (stock miner does about 3 per second)
You usually find a solution every 100 graphs (approximated value)
Then you would need about 350,000 solutions and a lot of luck to find a block

if you do the math that is at least 22 days to be lucky enough to find 1 block with gpu and about 286 days to find one using cpu mining.

So, you are better off using a mining pool that pays you per a share of the work.