If you are a total newbie, it is kind of difficult. But you need to check the team, search their social media profiles, even contact them directly, do a reverse image search to confirm they are legit. You need to understand the project and need the whitepaper. Need to compare the technology with similar projects to see if they didn't steal anything or if it is just a recycled whitepaper. You need to see if they do have a minimum viable product and be able to see it, try it. You can review the code they already have on github or similar repositories.

Those things, among others, will help you to detect scams.