I used married. How do I change or edit?
It’s up to you. If you prefer to keep you maiden name private, don’t edit. I believe my profile uses maiden and married.
How you edit depends on which profile you mean. If you mean the one in Family Tree that nobody but you will ever see, you edit it the same way you edit anyone's name, by clicking the edit/pencil on the profile's details page. If you mean your FS account profile, you can change the name(s) associated with that by going to a main FS page (i.e., not here in Community, but back on the regular www domain), clicking your name in the top right corner, and choosing Settings. I have the same thing in all of the fields, so I don't know which one is the one that Community uses, but I know that the one that's used to label your contributions to Family Tree is the "Contact ID", found on the Profile tab of Settings.
As for which name to use, that's up to you, and the choices include "neither" -- your Contact ID doesn't have to bear any resemblance to your real name. (I use my married name here because what got me started with the Tree was my husband's Famous Relative's profile, which needed all sorts of help.)
Incidentally, for your deceased female relatives / ancestors, always use their maiden name. This is not always so easy to discover, though. I have added IDs of women (based on marriage records) that turned out to be in the name of their first husband.
I know this is not your specific issue here, but please bear in mind the usual practice when adding a woman's name to Family Tree, or similar databases. You can, of course, add the married name as an "Alternate Name" in the Other Information section of the profile, which can be a help in finding records for her that are recorded in her married name.
Your username and email here in Community comes form your Contact Id and recovery email in your FamilySearch settings. How do I update the profile, email address, and other contact information on my account?