first find groudon on the seafloor cavern near moosedeep city.... use dive and go south...
you'll see a cave enter it and use dive again...you'll see team magma there..find youre way to maxie and defeat him...groudon would fly to sootopolis..go to cave of origin..then just find youre way to groudon....catch groudon...after that...the gym would be open...
use your groudon against the gym leader..but teach it thunderbolt first...
----p.s. help me too.....this is so easy...but i really forgot..where can i find exp. share????

go to the devon president and tell him ur done with his tasks and he should give u one