Anyone can give me any advice?
Yeah, DON'T!
A 3090 at 5 cents/kWh will get you randomly between 10-20 cents a day depending on the up and downs of the few coins left to mine.
So best case scenario free electricity cheap GPU you look at spending $1000 to make $100 a year.
Crypto mining is not profitable anymore, if I were you id buy Asic miner to mine BTC or Doge coin.
If I were him and did not even have a clue that ETH is not minable anymore for a month already I would stay out of any kind of mining.
When you have zero clue what you're getting yourself into it's far better to just buy the coins and hold them rather than burn money away.