Bougainvillea needs at least 6 hours of full sun a day to flower profusely and look its best. This plant also loves the heat. Not enough sun = not enough color.
When it comes to watering, Bougainvillea is pretty drought tolerant once established. It prefers a good, deep watering every 3-4 weeks rather than frequent shallow waterings.
When establishing (in the 1st couple of years), be sure to give your bougainvillea regular water. It’s subject to a few types of root rots so don’t over-water. The soil should be well-drained which will help prevent rot.