start off as (something)

To begin development from some particular status, condition, rank, etc. I started off as a QA tester, but I was eventually given the chance to be one of the company's software developers. It started off as short story, but I kept adding characters and plot developments until I eventually made it into a full-fledged novel. Hey, don't feel bad—we all start off as beginners. It's only through practice and experience that we get better!

start off as someone or something

to begin in a particular status, character, rank, etc. I started off as a waiter and ended up as the owner of the restaurant. This tree started off as a tiny seedling only a few years ago.