I just started in bonsa[
And you're making the same mistake as so many who start in bonsai.
Bonsai are NOT created by planting seedlings in a bonsai pot and keeping them small.
I was wondering if this type of tree is good to work with
I have no experience with this species, but I see they can give good results, if you use the proper techniques.
www.google.nl/search?q=delonix+regia+bonsai&tbm=isch