you could wetsand to get rid of the pebbly characteristics and then for a higher gloss go with a spray polyurethane. In the future you can eliminate the pebbly look by spraying closer and in heavier coats. Sometimes the pebbled look is a nice touch. Possibly post some pics so we can get a better idea of what you mean.
also to get a really high sheen finish when sanding consider using a rubbing compound equal to between 1500 and 2000 grit. It really smooth things out and costs about as much as a pack of sandpaper.