My name is Annie Jonasson, I'm an 17 year old (despite what my profile picture might suggest) writing what I know (so teen fiction), and I have never had a more difficult time finding a username than I did signing up for wattpad.com
Turns out there's a lot more Annie Jonasson's than you would think, and no amount of numbers at the end was going to change that... 
So I made my username the name of a character I fell in love with- Penny Shapiro
Thankfully, she has a less common name than me!! 
Author of Cal & Penny's Anti Bucket List (and a bunch of other embarrassing unpublished manuscripts), available here and on swoonreads.com