My life would suck without you
If you want to have some type advantage when you challenge Roark, you could catch a Budew on Route 204. Budew will start off with Absorb and will learn Stun Spore at level 10, which could be very handy for you. It learns Mega Drain at level 13 which could help you further. It'll eventually evolve into Roserade, which in my experience, is a very useful Pokémon.