My bonsai seems to be getting a little big. Should I start pruning? It is a jacaranda mimisofolia and it is about to complete one year of growth. This summer it had a growth spurt.

First... that is not a bonsai but a young seedling...
I am not familiar with the species but i think you need to start studying on how to make bonsai from seed. Contrary to what a lot of people believe bonsai are not made by putting seeds. seedlings in a tiny pot. The entire explanation would take me hours to type, so the search button is your friend...

acnologiaryu wrote: Should I start pruning? It is a jacaranda mimisofolia .

Don't prune it yet.
You can wire it lightly to give it movement.
If you wire it...Leave a leader growing up otherwise it will die.