While scanning for magic you see that the shield has a moderate abjuration aura. The scrolls and potions are also magical. You get a very faint aura of necromancy in the hold of the ship as well as the corpse of the recently killed creatures.

Just to be clear, there are 4 cannons, 2 in fair shape, and 2 in very poor shape. These are 3lb (ball size) cannons and each one weighs 800lbs, so each one will need to be moved across separately and take quite a few people to do it. It will probably take an hour or two per cannon.

This was clearly a trade vessel, so it has a lot of cargo. The cargo that can be salvaged is about 1/3 of the hold. But loading and unloading a ship is not a fast task. Normally the crates would be loaded and unloaded with pulleys, carts, and ramps. With some ropes from your ship and some work you can repair the mechanisms to lift them from the hold, but they'll then have to be loaded into the jollyboat and transferred over a few crates at a time. The cargo will take 8-12 hours to move all of the stuff that isn't completely ruined.