First game of X Wing this Saturday. Questions on potential list.

Try this to play with squads and upgrades. http://xwing-builder.co.uk/build

It also tells you where cards are (which expansions) and with friends you can always proxy them, as all the details for each card are on the x wing wiki here: http://xwing-miniatures.wikia.com/wiki/X-Wing_Miniatures_Wiki

Also you can read the rulebook for free online https://www.fantasyflightgames.com/ffg_content/x-wing/support/SWX01_XwingCoreRulebook_lowres.pdf to get familiar.

With the new stuff out now I am not sure X wings are so brilliant, it is a lot of points for not so much health.

Y wings.... they have had a huge boost from the S&V expansion, as the BTL-A4 title makes them able to shoot twice per round. Otherwise they have issues.

B wings are popular, though the meta seems to be shifting. You can also look into the yt2400 or yt1300 now it has restocked, the turrets can be nice.

I am also coming to adore the HWK, though more as a scum ship. It is a cheap support ship that can take a turret and help manipulate the game.

If I were you I might try buying:
S&V most wanted, plus an imperial Y wing and imperial Z95, plus an HWK. This way you expand both your imperials and also make Scum playable for you, as all of those work for both fleets. Most Wanted has the Y wing title you would want for Rebel too, and you end up with three Z95s, with enough ship tokens to field two as rebel or three as scum.

My impression fo A wings is that when kitted to be fun they cost a lot for the red dice they roll. That said my mate ran Tycho with PTL and daredevil for a mini game and it was insane quite how far he travelled post maneuver.

However with chardan refit is only 15 pyts as a nippy flanker. I've nto played with A wings myself, but they seem... difficult.