There's nothing free and good on Telegram especially if you are using something they own Telegram is the most popular chat application for groups but there are always attached risks using it especially if you're part of the Cryptocurrency niche.

One it's hard to distinguish a newly created account from a more established one because there's no profile history to look at, second there are so many impersonators its easy to clone one account and just an additional or changing a character on one username is already enough to imitate one account, and if you do not know how to configure your privacy there are so many scammers sending you messages.

And always check the groups and the account you're interacting it's a good platform for legit projects but also a good platform for scammers to scam.