Microsoft add account on PC?

I have a laptop and would like to add an account. One account has Microsoft Family set up. But wants to be able to play on the other without my time running out!

That will not do. If you bought the game in the MS Store, you also need to use the account games you bought it from because the license is registered.

If you have admin rights, it's easy: just create a new local user (without MS account).

It's about Steam games etc.

I have! Are the parents notified?

I do not think so.

And the things I do there are also no longer in the weekly activities? Or does that show more of the time?

At least not in the family management of Microsoft. In the router you can still see it.