If you're not planning on going full aggro and taking on a real player's base, try fighting some random sea monsters. Only take on what you can really defeat though! Defeating a sea monster will provide you decent rewards, like gold, experience, and resources. Your ship will take damage afterwards though so make sure to repair your ships in between trips. Your ships need time to travel to their target and back to base, so send them out before you do anything else. Consider them another part of your "queue", so don't forget about your ships.