Don't be shy when pruning...its all up to you!
this tree will need to be kept in check just about every other year or so...depending on location.
In Central FL, they get rather large, quite fast. They make so much fruit no one eats them all. Raccoons don't even seem to eat them...seems like only flies, ants, and people.
When I prune mine for the first few years, I just pinch tips, and encourage branching. Flowers can pop right out of old wood, so don't be worried that you'll be cutting off fruits! With only removing portions of branch tips, you won't be able to put a dent in fruit production!
As the tree gets taller, you may want to train the tree so the tallest branches are pulled horizontally....or cut off altogether after reaching a height of over 10 or so, feet.