first you get there and talk to wally. battle with him and kick his butt. Then enter every building until you find a guy that will give you rock smash(HM 06).then battle with the gym leader and kick his butt. Then go to your left and leave the city. go to verdanturf town. Then teach a pokemon rock smash and go inside the cave. use rock smash on the rocks to reunite the couple and open up the path. Then head back to Mauville City and go upward to use rock smash on the rocks up the road.
Extra Stuff:Go into one of the houses and talk to a lady. She'll state that she will trade someone her coin case for their harbor mail. Head back to Slateport City to access the pokemart and buy harbor mail. Then head back and make the trade. Get the bike from Rydel. Get contest pass from the first pokimon contest center in Vendanturf town.
is this the best sig you could think of?^team ut 4 life