How do I change my Ask ubuntu username because I pressed enter by accident and now I have this one.
You can change the display name easily. Go to your user profile page, and look for:
Click the edit button, and you should be able to change it via this:
Then press one of the orange buttons at the bottom of the page:
Also this might occur if you try changing it to often:
Which now means I cannot change the capital
You should be able to change it from your profile page (shortcut).
But if you can't change it, let me know what you want it to be and I can edit it for you.