Mine altcoins and HODL in bitcoin

I think you should try mining because your 0.0051/kWh is practically free. If you are not ready to buy a modern ASIC, then buy an ASIC S19 series for 300-500 euros and try. Do not be afraid to gain experience in practice, if you succeed, you will find an investor for 4-5 modern ASICs and expand to 16 kilowatts.
You really have a price of 0.0051/kWh? There are no such prices in France.

This is good for mining if you don't have any additional expenses and you have permission to mine. For example, my electricity cost is less than 5 cents, but I can't consume much electricity in a private house, so my mining will be limited to one or two ASICs no more than 7 kilowatts per hour.

What most mining newbies oversee is how the more or less steady grow of global hashrate and thus difficulty continuously lets your own, usually constant, hashrate earn less and less, because your share to the global hashrate gets smaller and smaller. This is one of the main profitability killers.

If your investment in an ASIC needs about one or two years to break even, and the usually ridiculous prices of state-of-the-art ASICs demand quite long break-even periods, you should have a look how mining difficulty changes over such period intervalls.

Compared to a year ago to now difficulty rose about +46.3% (a year ago set to 100%); compared to two years ago to now it rose about +145.5% (see difficulty chart).

If anybody thinks mining is sort of like easy-peasy money printing, let me tell you: it is not. DYOR and do the profitability math correctly. You're better off to buy Bitcoins with your money when there's a correction or bear market. Now is maybe not the best time as we're pretty near ATH. Others suggested DCA which isn't a too bad strategy if you feel you don't want to wait.

Nobody knows when there will be a correction or bear market and which lower levels we will see in the future.

If you are new to mining, maybe you should give up on this idea and just buy bitcoin with your money? The end goal for you is to get bitcoin, right? Maybe then remove the extra link in the form of mining when you achieve this? So you will get bitcoin here and now, and not some time later in the mining process.

As a newbie, I would do exactly that. And later, in the process of studying information about mining, I could try the mining process itself.

€3,000 = 0,031 BTC