Topic on Talk:Differences between Wikipedia, Wikimedia, MediaWiki, and wiki

I don't know how to put my profile picture on

Most people don't use an image to represent themselves on any of the Wikimedia projects. If you want one, you have to make sure the image is released in the public domain or under a compatible copyright license by the person who wholly created it, then it can be added to Wikimedia Commons if it's not already there.