I have:

1. Core set

2. Twin Shadows

3. Return to Hoth

4. General Weiss

5. Royal Guard Champion

6. IG-88

7. Han Solo

8. Chewbacca

9. Rebel Troopers

10. Rebel Saboteurs

11. Bobba Fett

12. R2-D2 and C-3PO

13. Stormtroopers

14. Wookiee Warriors

15. Grand Inquisitor

Can I make a competitive squad with what I have?

Sure you can. It won't be top of the line with EVERYTHING you'd probably want to be super competitive but will definitely be enough to take to a store championship.

Try this on for size

8 - eSabs w/Targeting Computer

8 - rWookies

3 - Gideon

2 - C3PO

9 - eTroopers

10 - Luke Skywalker

If you are interested in being a little more competitive you could do a couple things depending on what units you want to play. If you get one of the new Jawa packs it comes with an upgrade card that will let you use IG-88 competitively. If you want to focus on Rebels then the Jedi Luke pack and Hera and Chopper are all really solid. If you are thinking about trying the empire on for size then I'd say grab Captain Terro, Bt-1 and 0-0-0.

If you aren't interested in getting any more blister packs then the newest box Jabbas Realm has some very competitive figures that are considered solid like the eJet Troopers, eGamorean Guards and everyone's favorite the eWeequays.

What do the e and the r mean? Elite and Regular?

Thanks, any command deck tips? I plan on getting everything eventually LOL

Yeah it's just a letter for Elite or Regular units. For command cards off the top of my head from what you have some solid ones to include in almost every will be

Take Initiative (core)

Negation (hoth)

Element of Surprise (core)

Urgency (core)

Planning (core)

Fleet Footed (core)

Urgency (core)

Deadeye (core)

All of these are solid filler cards for any list you are building right now. Obviously you'll want to add anything else that might be list specific.

this list isn't exactly competitive, but i you learn you to dodge the RGC and TGI in and out of combat, it can go pretty far:
15 royal guard champion
9 The grand inquisitor
9 e Stormies
5 e Probe droid
2 r Officer

If you want 6 activations you can drop the e probe to an r probe and add another officer. If you get the chance, grab agent blaise's pack as it has zillo technique, which is arguably one of the best 1 point upgrades in the game.