And it is more than difficult to know that, but with some experience, you will see and find those which are scam easily.

Just look for that

1) Whitepaper (if it is a  copypasted or not)
2) The telegram channel (if there are too many bots or not)
3) the website (if it is a bought one or not)
4) The discussions on telegram, and to see if they all are bots or not.