

Thats just the gen-z version of not investing in apple in the 90s. Missed opportunities are not the same as actual mistakes, they all involve risk and things that blow up like BTC are rare and hard to see before they are take off. Its best to not kick your self over not having a time machine.
Credit cards are fine if your responsible with them. Don’t run balances (unless you have to), use them as a buffer for your checking account, not a loan. Try and find one associated with your main bank, set a low balance limit (less than your savings, and try to get your savings over that limit), has decent rewards and has low fees. They are not in the business of screwing their existing customers, unlike a retail card, which has less of an incentive to behave.
The key adventage if you good at being a boring banking customer is dispute resolution. In the case of debit cards, you have to go after your own money. With credit cards, the bank has to go after its money, and they can put more effort into it than you can. (Plus enough credit card disputes will cause the card processor to drop the vendor, so… You have that card to play).
And your 100% correct on the micro-loan nonsense, thats not finance or credit, they are a scam.