How do I register and make a password to access JotForm?

I see you have registered an account username related to your email address.

If you need is to change your password, go to your account > settings and change it there.

If on the other hand, you wish to password protect a form, follow these steps:

Go to the My Forms page, pick a form, then click Edit Form

Navigate to the Settings tab, click Form Settings on the left panel, then Show More Options.