This Doctor will heal your Pokemon after the battle. If you need your Pokemon healed again just talk to him. To the west, on top of the hill, is a male Backpacker. He has a Tranquill with Roost, which restores HP but makes the Pokemon Normal type for one turn. That means you can hit it with Ground-type attacks for that turn.
West of her are BlackGlasses. They boost Dark-type attacks by 20 percent when held. Continue north and talk to the man in black. He will give you a Soft Sand, which will boost Ground-type attacks by 20 percent when held. Walk northwest and you will find a bunch of things that look like statues. They are actually Darmanitan, the evolution of Darumaka. South of the Darmanitan is a Fresh Water and a female Psychic to battle.
West of her is a Super Potion. If you continue walking west, you will find a Heart Scale in the northwest corner of the Desert Resort. Heart Scales can be given to a Move Relearner to teach a Pokemon a move that has been deleted. From the Heart Scale, walk south past the tower to find a Psychic running around. He has a Yamask, which is an interesting Pokemon. Yamask's ability is Mummy. When you attack Yamask with a physical move, your Pokemon's ability will be replaced with Mummy. It can mess you up if your Pokemon's ability is a big part of your strategy. Yamask is a Ghost-type Pokemon so Normal-type attacks will not hit it.
He will also give you a Rawst Berry. Walk south and you will find TM 39, Rock Tomb. This move deals damage, lowers your opponent's speed, and may cause flinching. It's an okay move to use if you find yourself needing a Rock-type move in the future. Make your way back to the female Pokemon Ranger and go south until you find a Fire Stone. Walk east to fight a Psychic pacing back and forth.