can I add a second user to my account?

Yes, it is possible, if you are referring to your JotForm account. 

They are termed as sub-users who can manage your forms and submissions. You can assign privileges to them like editing forms, viewing submissions.

Please note that your sub-users will need to have a separate JotForm account(can be a Free one). The number of sub-users that can be added into an account is dependant on your current plan.

Related Guide:  How-to-Share-Forms-with-a-Sub-Account-User