What to do in Pokemon Pearl?

I've defeated four gym leaders, but I stopped playing for so long that I have forgotten everything I did before. Please help me, just tell me what to do next so I can get on track. I don't have surf or rock climb, and I can't get to Celestic Town, Cave City, Sunyshore City, Snowpoint City, or anything that requires surf. I also can't use strength to push boulders because I only have four badges. Please help, this is driving me crazy.