The best is to stay away from new projects, there are still some good altcoins in the first 100 rank ymthat you can invest on, but know generally that altcoins are risky just like luna that was in the first 15 rank that is not in first 100 in just few days. New projects are more risk.

Go to Coinmarketcap and check the contract address of the new project

Follow the developers like on social media, question them and know what the project is all about.

This is one of the most important part, read the white paper, check for plagiarism, if plagiarised, it is a scam.

Even a new project and become pump and dump. New projects are highly risky.