You may want to change your password to access your admin panel from time to time for security reasons. Here is how you would go about changing your password.
First you will go to SYSTEM > PERMISSIONS > USERS.
Once you are in the "Users" tab you will click on your user account. Then, inside your User Account, you will be able to update your password. You will need to enter in your current admin password in order to be able to change your password.
Once you are finished click Save Config.
Now you'll want to flush cache:
SYSTEM > CACHE MANAGEMENT. Select Flush Cache Storage at the top right of the page.