Safety of data access

Hi. I have some questions about teamviewer qs.

I used Mac OS. Last week, a guy helped me install parallels desktop by  teamviewer qs . I told him my ID password,also my PC password. After the parallels desktop is already done, I accessed the windows system and opened some pages. At that time, the remote connection of teamviewer is still opened on my Mac. ( it means he can still access my pc remotely)

My question is, if he do something such as copy my files or change some settings on my Mac, can I view that ? Because I change to windows at that time and I can not see the teamviewer on windows.

i am worried about my file safety. Looking forward to hearing from you.