Hi indy! Welcome to PC!
To secure an avatar... view the top of the main index page...up on the right side it will say : Indy39's Profile. Click on that. Then, on the first line of preferences, click EDIT (on the right) That page allows you to fill in what you want for information displayed, signatures, and lower on the page AVATARS.
Type in the location of your picture, abiding by size. ( You can right click on the picture, select Properties and a window will come up showing you the size of your picture, so you can tell if it's too large or not

)
Make sure you put the tag on it [ url ] or [image ] AND REMEMBER to scroll to the very bottom and click on SUBMIT. Your avatar should show in your preferences page, so you can tell if what you did "worked."
For signatures, try using a wording instead of an icon or pic first, to be sure you figured it out (less frustration?) TC!