Did I make a mistake?

[examplens]

Your statement is conflicting with each other. You are new to cryptocurrency but directly jump into the casino. It's hard to believe that, even I am a long time with cryptocurrency but still have not much experience with casinos nor I am interested.

and for me this is surreal but he is a gambler and everything is possible.

I’m completely new to crypto and have no experience with transfers, transactions, etc.
... I wanted to do something useful with them. I tried to make my deposit here https://betinhell.me/bitstarz-casino-bonus/.

Seriously?
Completely new in crypto and you want to do something useful with your BTC. So, what is most useful for you? Deposit it to the casino? Really?

Did I do anything wrong? Where are my bitcoins? I’m really starting to panic. Help!

Yes, you do something wrong. Don't gamble with money that you can't afford to lose.

[smyslov]

A lot of OP's actions is questionable if this is true why made your first deposit in a casino, it should be on a wallet that you own to see how it works and to the general idea on the transfer, and if he is serious about his issues he should do a follow up since he posted his issues here, it seems OP just want to promote that review site if it is it backfired, that's not the way to promote a site.