how to i switch my account from being assigner to assignee on the computer?

Upon checking your account, you currently don't have any forms and are being assigned to multiple forms by simplysocial.

You can create new forms of your own then assign it to anyone you'd like to fill out your form.

How-to-Create-Your-First-Web-Form

https://www.jotform.com/blog/use-jotform-mobile-forms-to-assign-forms/

However, if you want to assign the forms that were assigned to you by simplysocial, unfortunately, that is not possible.