Agree that trading requires a lot of knowledge and skills but in my opinion demo isn't good to get experience. I believe it's better to use a small account with real crypto or money but it shouldn't be disaster if you lose it all.
Trading on demo and with real money is different psychology.
With crypto you can get huge returns. However, it doesn't come easy, in a split second you could get or loose a large amount of money. This means crypto trading is exciting, and it can be very difficult to keep peace in mind under heavy pressure.
The easiest way of making money in crypto is investing longterm. Rather than trading you can buy coins, hold them in your wallets untill the price appreciates and you sell and make your profit. Of course you have to make some research about the coin, and be convinced it has potentials before investing in them.
Another way you can invest is day trading, which is a trading strategy where investors buy and sell orders for multiple times in one day. This requires more knowledge and skills. I suggest you use a demo account.