Fantina

The highest-leveled place for you to train at the moment is around Pastoria City.Fantina has Drifblim lvl 32,Mismagius lvl 36 and Gengar lvl 34.Electic moves would work well against Drifblim.She is easy to beat if you have a Ghost-type(or dark,if you play pearl there is Misdreavus,diamond has Murkrow,either of them is good),I beat her with my Floatzel though(it knows pursuit and crunch).Her Pokemon are mid lvl 30s,so your Pokemon really NEED to be at a higher level(no offense).lvl 40s should be enough to beat her and I'm going to assume that you don't have Misdreavus or Murkrow.Train Floatzel to around level 30 it will learn crunch,80 power dark type move,evolve Luxio to Luxray,train them up to about lvl 40 and those two should take her out.Just be careful with Drifblim's ability(aftermath,takes off your HP if you hit it with physical attacks) if you don't want to waste 1/4 of your HP.

Hope that helped!

Looks like you'll be okay.

As for training, just use the V.S.Seeker or something.

Hay I don't think it is possible to beat Fatina with such lower level Pokemon ou can ty leveling them by batteling wild Pokemon or if you want to cheat them but only use cheats as a last resort. I cheated most my Pokemon but all that does is drain all the fun out of it so level them up so they can stronger then you can beat fatina.