There is no way to directly upload pictures to your permies profile. Instead, the picture should be uploaded to somewhere on the internet first. You can even upload it to a post on permies. Speaking of which, how about creating a thread in our introduction forum to introduce yourself? You can upload a picture of you to that thread.
After the upload part is done, you can grab the image link and set it up as your profile picture from My Profile -> General Information about yourself -> Picture.