When you start a new game, you'll first see an opening. After that, write down your name. You'll now be forced into a battle.
This is an easy fight. You'll have a Lv50 Salamence with the moves Earthquake, Dragon Dance, Brick Break, and Dragon Claw, and your enemy is a Lv50 Metagross. Defeat the Metagross with two Earthquakes as only this move is strong on him.
Watch the short scene. You'll find out that you were just in a battle simulator. First, get used to the controls and to check your starter Pokémon, Eevee. It'll have four attacks: Tackle, Tail Whip, Bite, and Sand-Attack and will be at level 10.
Go to the elevator and head to the second floor. Talk to the professor to learn that Jovi is missing. First take the elevator back down and go west to reach your room. Go in and open the treasure chest to get your P*DA. Now that you have it, go back upstairs and find a guy lying under a table; talk to him. He will tell you that Jovi went to Doctor Kaminko's house and the location will appear on the world map. Go to the first floor and head south to exit the lab. Take the southern path to reach the world map, which has your new location to head to on it. Head to Kaminko's house!