Hi there,
I'm here to help.
If you just want to sign out and remove your account from that PC without deleting the account itself, Please try to go Settings > Accounts > Email & accounts under Accounts used by other apps, find your account and click it, hit Remove. Also you can go to Settings > Accounts > Your info, If you’re logged in with a Microsoft account, switch to a local account first if possible, then remove yours. This should log you out and hide your account from the sign-in screen, without deleting the actual account. If it’s not letting you, the PC may have admin restrictions in that case, ask IT to help clear your profile.
Hope this helps!
Warm regards,
Cherrelyn