Locate or search for the user who you want to assign a license. There will likely only be your single account – click your account
Click Edit at the end of the user row. This will open a window.
Choose the User Type to assign, selecting “Licensed”.
After choosing the User Type, use the drop down to select the license. There should be an indication that you have 1 available user license. Click that.
(Optional) Assign add-ons by checking the boxes for the add-on. You will not likely have any add-ons, so skip this step.
Click Save.
The license is now applied to your user account and you can use it immediately.
If this doesn't fix your issue, please describe in more detail, and I'll try to help with additional guidance.