I fully understand this is your aquarium, and it has to be according to your liking. But the great benefit of a good forum is getting advice to avoid problems down the road.
If I were you, I would return the angelfish. The larger tank may or may not materialize in time; and even so, bear in mind it should be a 4-foot like a 55g so you can have a shoal of angels (5+). A "pair" is not the way to go, unless one is breeding them and that is a totally different issue. You are working toward a long-term established aquarium, and at the moment angelfish are not suitable.
When fish like angels are young, they are one thing; but as they mature, instincts become more evident, and stress can turn them into very aggressive troublemakers, as other members here have previously mentioned in older threads. Being prepared for the probable is better for the good of our fish.
In a 10g you can have a host of variety in small fish. We can discuss options later if you like.