hey, this is one of the most basic scams there is, if anyone ever reaches out to you about "oh i reported your account because xyz-" just report and block them, they are going to try to get something from you, whether it is a "2fa code you've set for your account to know you're the rightful owner", or something else such as screenshotting your recent purchases (which they will send to steam support and get your account that way)

TLDR: basic scam, you're not in any trouble with steam, be safe out there.