Yes! To change your username, please:
Log in to your account
Hover your mouse over your name or “My TpT”, and select “My Account”
Click “Edit” on your “My Account: Basics” page
Enter the username you want (between 4 and 20 characters, no punctuation or spaces) in the username field and click “Save”
If the username is available, you’ll see a message confirming that your account has been updated.
If it’s not available, you’ll see a box next to the username field (“This username is already taken.”) In that case, you’ll have to try alternative names until you find one that’s available.
If you're a Seller, you may want to consider adding an alias to your account instead.