Thoroughly research everything that you want to buy. Check if employees of the cryptocurrency project have LinkedIn or easy to find contact information. The crypto community has a strong foothold on twitter. Search relative hashtags for cryptocurrencies you are researching and see what twitter users are saying about it.
If somebody you don’t know messages you out of the blue about a cryptocurrency (on Discord, Telegram, Facebook, and Instagram) it’s most likely a scammer. Report them and block that account.