cruisers are a bit skill intensive to get the best out of is the problem...
for one thing, if you're still doing lvl 1 missions, you're probably fighting frigates, which cruiser guns will have trouble with. the destroyer meanwhile is built for taking out frigates.
tbh, i'd say stick with the destroyer for a while, whilst you skill up for a cruiser.
your going to need all sorts of skills... i cant remember names, but basically most of the gunnery section (to shoot stuff well), and a lot of the electronics and engineering sections (to fit all the stuff you want, and to toughen yourself up.)