This mission is easy. It is mainly about taking the professor to fall city.
1. After you finished your rookie mission, go up to Lyra forest, and keep going up.
2. At this stage the professor will tell you about poke assists. Listen carefully, because this is a big part of the game.
3. As you go up you will see a bunch of hay blocking your way. Go west, and you will see a torchic. Catch it and burn the hay.
4. Go down, and you will see a giant tree with little pokemon playing around.
5. Remember to take some electric pokemon here. These pokemon will charge your styler, which is very handy in case things go wrong. So catch a pichu.
6.while you go east, a combusken pops up in the bushes. CAtch it, and use it to burn the tree. Keep going up and go to the cave.
7.This is the Krokka tunnel. Head north, then east. There is an exit at the south, but you don't need to go there. Just go to the north path.
8.You'll see a dugtrio, and the proffesor comes near. Suddenly 2 rockfalls fall and you get seperated by the proffesor.
9.A paras should've fallen too, so catch it and cut the fence at the north.
10.Head north, and ignore the rockfall blocking another entrance. Catch a magnemite in the way to get some energy. Go to the entrance next to the rockfall.
11. You'll see a poliwag, catch it because you'll see a powerful pokemon soon.go south, and go to the exit.
12. There is the go-rock squad bullying the proffesor, and soon they'll go away. go east, then south to go out of the cave.
13.There's a Rhydon rampaging, and you must capture it to complete the mission. Use Poliwag's water assists to finish him off. Rhydon will go away.
14. Go east and you will see a town. It is Fall city.
15. Mission clear!