Are you talking about the docks or in eldrite because if your talking about eldrite theres no pond there , do I need to buy the fishing rod in the convenience store?
I'll go over the entire plot. Go to the porn store and talk to the lady, Pearl. This will let you meet her at the docks, which will let you fish and buy stuff from her booth after you buy the fishing rod at the convenience store. You can then buy the fishing spot pamphlet, which will let you meet her at the swamp in Eldrite, but only at night. Then you can buy a case of beer from Pearl in Eldrite