Go to your blog by clicking on your name anywhere you see it. Sometimes you have to click on the little guy/avatar.

Or you can go to the top right and click on your avatar picture next to the word Post (the little gray guy again until you put in a profile pic) and then click blog to go to your main blog page) and click on the number of followers just under your name. (currently says 3 followers)

Then click the mute button next to a-a-a and it takes about 3 seconds to update that. (approximate blockchain speed for recording any and all actions on steemit)

There is an app on smartphones called eSteem that you might want to try because it makes it so you can use photos from your phone for your profile pic or cover photo and it's relatively easy to use to select photos that way. (if you have a selfie on your phone, etc.)