You can do a lot of things to detect scams. Most of the time it is quite easy to do, if you actually take your time asessing the project.

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.

Now, if you fall into a scam, a scam is people stealing money from you. You could theoretically make the report to your local authorities. But it is an unregulated market, so depending on the country, if they are located abroad or if they cannot be identified, it would be tricky. Will depend on your authorities how far they go in the pursuit.