Hi Jessica, welcome to SitePoint
On the top right of your screen you should see My SitePoint - click this link and you'll be taken to your Member Control Panel page. On the left hand side of your screen you'll see all the options you need! To edit your profile simply choose Edit Your Details under Your Profile section
Here's our FAQ on other sections of your profile you may wish to edit down the line!
Enjoy your time on the Forums!
All the best,