Sandra G, I will try to explain how I got mine, I hope you have a bit of knowledge with computers and the Internet, obviously you have some knowledge. (BTW I don't have a great knowledge of the Internet)
First, Google Avatars and find one that you like, save image as at it will go to your pictures on your computer.
Second, go to My Profile in the blue box under Food And Recipes, click on that and it will bring up your Profile,
Click on 'Edit Your Detail'
Third, Go down to Photo, Click on the 'Browse' button and it will bring up your files, find the Avatar that you saved, click on that and it will insert it in the Browse box, click on Update and all should be good.
That is how I do it, probably not the right way to do it but it works for me. I tried to put in one of my Photos from my pics but it cover two pages on here so had to delete it and get the Avatar off the net. Good luck with it, hope it works for you. Cheers.