Think big. We ran a campaign for almost a decade. Now ours wasn't exactly cohesive and we swapped GMs fairly often if someone had an idea to run with, so our adventures were often one off adventures led by the characters. Usually they were fairly loosely run. The GM had an idea and presented it at the start of the adventurer as part of the story and we went with it. We had Eric Nightdrifter who was a failed jedi(template) trying for redemption and to figure out how to properly use force powers to correctly handle a lightsaber, I forget the smuggler's name but he started as a "I want to be Han Solo but cooler," character when we were HS freshmen. I played a Twilek gunslinger and pilot working towards freedom of Ryloth from the Hutt slave cartels(at the time there wasn't a lot of info on the subject as there is now). Every adventure kind of moved someone forward in their personal stories but like I said rarely was there a sequence of adventures tied together. We only dealt with a movie character once in the game where we were learning to play and were not expecting to keep the characters. We went through numerous ships, pet droids, used storm trooper bodies as shields, started adventures being woke up tied to poles in the jungle naked surrounded by raw meat, impersonated Imperial admirals and stole a super star destroyer and found weird cults with ancient jedi and sith artifacts.

Because of how expansive star wars is I urge you to consider perhaps an over-reaching story but make the adventures rough outlines. There's no telling what PCs will do and head off to so you want to play loosely with the adventure. Think big. Everything in Star Wars is big. Big giant war machines and stupidly huge ships, awesome planetary vistas and space worms, larger than life characters.

I don't know what your plan for the campaign would be but starting perhaps as privateers vs or for the Empire. Intelligence agents for or against the empire. A young jedi padawon who was overlooked in the Purge and is trying to teach himself jedi abilities while hiding from the ever searching eyes of the Inquisition or like my friends character, a jedi who couldn't take it, earned a couple dark side points and spends most of his time in a bar with a bottle reminiscing about the good old days but is trying to make a comeback.

What system are you using? We played the older WEG d6 system(which is now completely free and downloadable) which allowed for absolute freedom when making characters since it was a classless system. Also very easy to GM since everything is based off a D6 and a simple difficulty system. I looked into the FFG system and found it far too restrictive and complicated for whats supposed to be a fast smooth game.