If everything is happening on Telegram the you need to be very careful because this might be a trick to rob you of all your earnings.
Not might but definitely it is just a way to scam, he would only be scammed. Seeing that scam site alone should have let us known that they are planing to scam. I am still always getting surprise that some people will be scammed this way which is avoidable.
If you want to enrol for his teaching, one on one class then that should be your own opinion since you he had traded for you with good profits.
The one on one class is not face to face, they met on a telegram group, believing who you do not know alone is foolishness when it comes to money, even the person you know might scam you not to talk of people you do kit know.
These kind of online lessens, classes or whatever someone can call it are only a means some people are using to scam people.
So do not trade or gamble on platforms that are new in the gambling and Crypto world. It is a risky attempt and you should know what you are taking yourself into.
Exactly my opinion.
@TomChicker, check lists of exchanges here:
https://coinmarketcap.com/rankings/exchangesSome can still be shaddy, make more research to know which ones are best for you.