If you're aiming for bonsai, go relatively shallow and wide, but not a bonsai pot yet. This will get the roots growing outward to help build the nebari - the cool looking surface roots.
Taking an old bucket and cutting off the bottom half and drilling drainage holes in the bottom works well, or cut down the top of an appropriate sized nursery pots.
You'll want allot more room for roots while you're still growing it out. This will help it grow faster. Don't go to a small pot until you have the trunk shape and basic branching where you want them.
BTW, welcome to the forum, and thanks for adding your location. It makes a big difference in what sort of advice you get.
There are several more active members of the forum from Arizona. Look around, and talk to folks, and you're likely to find them.