Hello @Chrissanne Long35
you can change the state of any member by clicking on Edit profile of the user > scroll down to the Admin tools > Status > Suspend by moderators.
that will block the user from doing anything. and he need to contact with you via E-mail to reactivate his account.
This link will explain more on this matter
"Suspend" User Status: Released on December 20th, 201931
Hope that will help you.