what can you suggest to us and how to find out if the project is a scam
It's not so easy to find out a scam, even legit altcoin project can end up as scam. On the other hand, the right coin, bought in the right moment and (very important!) also sold in the right moment can give nice profits.
On the long term altcoins have disappointed me. So selling is just as important as buying.
But can you find out those moments? I'm not so sure. You have to be either very lucky, either very experienced. Or both.
So you better step back and get on learning. Crypto is not a simple "get rich quick" world. Altcoins, especially, can easily be called "get poor quick".
Stable coin like bitcoin , Ethereum and bnb is a good coin to be invested if we are newbies or new in the word of crypto.
Just to make sure... stable coins is a term used for coins pegged to certain value (usually USD or gold), so Bitcoin, Ethereum or BNB are not actually stable coins.
And if you want to call them good coins, I will agree on Bitcoin, but not on those altcoins.