Every signed-in user — regardless of role — can update their own name and password.

1. Click your name and avatar in the top-right corner of the admin panel.
2. Choose Profile from the dropdown.
3. Update your Name and/or Email, and click Save.
4. To change your password, use the separate password section further down the same page — enter your current password along with the new one, twice, and save.

Password requirements (minimum length, and so on) are set site-wide by an administrator and shown next to the field if what you type doesn't meet them.