The profile name you have is the name of your character. You edit your profile by clicking on the User CP just under the banner at the top of the page, and fill in your character's details there, like History, Appearance, Personality, etc. If you have named your profile wrong, which it looks like you have, seeing as your profile name is "Thunder Raine" but you seem to be playing a character named "Ajax", you can ask Admin to change it for you.
This site works a little different to most, so it may take you some time to get used to it. I encourage you to read some other posts and threads, so that you understand what is going on in each forum, before you post your own replies. It's really important to keep track of what others are doing so that you don't interrupt an important plot or upset anyone OOC by ignoring other things going on in the RP.