What should I do with flagged files now?

Okay, so I’m running the total system scan on my mac for the first time. It is coming up with a lot of (maybe 50) the yellow upside down yield sign with an exclamation point files, and about two so far that it flagged with the red stop sign and ex point.

What am I supposed to do with these files when it is done? And how do I know if they are important or not?

Thanks

P.S. I am trying to identify anything that may be affecting my system that is using internet data that I am unaware of. Burning through my limited data plan with very little use on my end that I am aware of. Trying to determine if it’s my system or my isp’s data collector.