I was looking at the ship weapons in the core rule book and I started to wondering how can I tell how many attacks I get with a ship weapon. Like the z-95 has light laser cannons that are linked. Do I just get one attack with that weapon or two?

One attack. Spend 2 advantage to activate linked to get an additional hit with normal damage plus uncancelled successes.

Yeah, remember you only get one action a turn. Attacks are actions, so unless you've got a talent that allows you to take an action as a maneuver or something, it'll always be a max of one attack per character per turn

Keep in mind that an attack action is not simply one pull of the trigger or a single blaster bolt. Rather, it's the total act of lining up a shot in a way that suits the narrative. It could be a single snap-fire shot that takes out an opponent, or it could be a blistering hail of laser fire that the target dodges and weaves valiantly but there's just too much. Both are equally valid narratives. The linked option shows that you were successful in hitting with both weapons, even if functionally the ship was hit with two blaster bolts from the same cannon. It's all in how you narrate the dice.