So I bought a handful of Armada stuff on clearance at Barnes and Noble, including a Core set, a couple Imperial Raiders, an Imperial Star Destroyer and a Rogues and Villains pack. This seems my best build so far, but maybe you guys can help a new guy out.

http://armadawarlords.hivelabs.solutions/view_list.php?token=45870&key=96be2e74b74be1ec995a83756789fe79

ISD-II: If you take an ISD-II then put ECM on it. Otherwise drop it to an ISD-I and save a good chunk of points. also add Gunnery team (assuming you don't take Advanced Gunnery as your red objective). Finally if feeling flash think about XI7 or leading shots on it. Relentless is good, drop Nav officers as they just compensate for inexperience. Once you get 4 games under your belt you will be ok.

VSD-II: they are expensive so I would drop it to a VSD-I and maybe add boosted comms and flight controllers. They work ok just vanilla too.

Raiders: Cheaper raider-I is the better of the two. Adding APTs is nice but probably better if you take Screed or Vader as an admiral. You could instead add Ordnance experts too but it gets costly.

Fighters: are ok. You could instead take Howlrunner and loads of Tie-F but it is nice to have a bomber to attack ships. If you want to save points for more ship upgrades a standard firespray is also a good choice.

Given the limitations of the expansions you have and the upgrades that come with, what you have is pretty good.

Ordnance experts on the raiders is pretty good, especially since you'd also get to reroll anti squadron attacks.

Since your ships have so much anti squadron capability, id consider trading some of those ties for either gunnery teams on the ISD and VSD, or trading in IG88.

Also, dropping to the VSD I also sounds like a good idea. You could use those points on some ordinance upgrades, like ACMs and Ordnance experts. Most people have found that the VSD is either at long or close range, rarely in just medium

Solid advice here- also, check around and you might find someone local to you for a pickup game too!