It sounds like you need to make a local account and use it by default instead of your admin user, and not give them an admin account or your password next time. Or their own device and let them lock selves out and see how much fun it is.
They have locked you out now. There is no easy way back from here.
if you aren't computer literate I would take it to store and ask them to copy all the documents you want off before resetting win 10. All you will be able to do is copy the documents off the PC and start again. Fastest way would be a factory reset if laptop came with win 10 installed, it would revert it back to when you first got it. It would delete the user off the laptop and you would have to recreate it again, and install everything again.