Hi Trude,
Really cool to see your enthusiasm for mining!
What I'll say is people always hate on people entering mining but everyone has to start somewhere...
Where I am now, I have 14 GPU's all together - I didn't just have them lying about lol I started on a really crappy laptop and grew from there. So don't let anyone put you off. Worst case scenario you would earn a few cents a day and hodl hoping prices increase massively - which has happened time and time again. Every time you see posts from like 2013 on reddit there's someone pointing out 'bitcoin mining isn't profitible'. Every single one has been re-posted at later dates highlighting the massive profits they would have made from bitcoin's rise from $300 to $20 000!
The better and better equipment you have the more profit. I read about how buying crypto is gambling and mining is a business. It's definitely a lot more true for the really big players in the crypto world but relevant to everyone. I have solar panels on my house and cheap electricity so it's very much a passive income for me, could be for years and prices could explode...
Even though you wouldn't be able to mine bitcoin, nearly all coins are tied to it (in price) or could increase more. If you happened to have a high end/gaming computer that would be best. If you want any time lengths for mining one Monero I'd need some PC specs...
Another thing, I've seen whales talking on twitter about how if you're running a node and mining a particular coin then you're a 'first class citizen' in that world and I see their point:
You're strengthening the network - couldn't survive without transactions being verified
Your rewards (coins) are actually decentralized being anonymous in most cases - buying from exchanges is hardly part of the decentralized revolution so to speak

Sorry for the essay lol but my advice is you should just give it a go whatever equipment you have and see where it goes. If you think prices are likely to go up a lot in the future, even quite a small investment could be very profitable.
Thanks