Your profile is your public facing page telling others who you are and showing what you have contributed. Many of the boxed sections on the left are self explanatory, but if you have a question about any of them add your comment in the box below.
The red arrow points to an image, click this image to change your profile photo or avatar; an additional box with options will appear, choose which you prefer and when complete click SAVE:
The first orange arrow points to your profile photo (in this instance it is a system generated avatar). The second indicates how many content items you have contributed to the site as a whole. The next two are self explanatory.
On the right are some additional controls:
Edit Profile will open up an additional box where you can add your birthday details, an 'About me' section and whether you want to enable or disable status updates (these are messages you and other members can leave on your profile).
Cover Photo will allow you to adorn your profile header with a nice cover photo - you can change this as often as you wish. Photos must be on your device as this is an 'upload' only function.
See my activity - does what it says, shows you a list of all your activity throughout the site (everything that is public, nothing that is personal).