If you are storing your cryptocurrency funds on Revolut or any kind of exchange/platform, you do not technically control and own the cryptocurrencies. In order to store for large amounts and long term it is recommended to move your funds into the wallet that you control.
Having a hardware wallet, Ledger, in your case surely helped you to ease the burden of maintaining secure devices for the funds. I suggest you utilize it fully. Also, if you need resources to learn deeper about cryptocurrency and how to store it safely, Ledger has a wonderful source you can take a look at:
https://www.ledger.com/academy.
Thank you sir! I got it and completely understand it. My only concern is if i want to buy more crypto or any other crypto with euros/usd , which platform should i use ? I know ledger has Ledger live , but a friend of mine has a Ledger for stocking and he's buying crypto from Kraken . He said that it was cheaper to buy from Kraken than Ledger Live that time. How can i know that or check that?
Another friend of mine uses only Binance for example.
Your current choice, Revolut, is not what most cryptocurrency users are using. Binance is the prominent one followed by Kraken. Both exchange and others have their own advantages and disadvantages, so you might research what suit you the best.
If your concern is the fee, note there might be a deposit fee and trading fee that you should be aware of when comparing each exchange.
For example, you can take a look at such information here:
Kraken:
https://support.kraken.com/hc/en-us/articles/360030303832-Overview-of-fees-on-KrakenBinance:
https://www.binance.com/en/fee/fiatFee