I haven't actually played Star Wars FFG on here, so this is generalized advice. Just click on "Create Game", it's free to create as many as you want. There will be a drop-down menu to choose the Character Sheet. Start typing Star Wars FFG and you'll see there are 2 different character sheets to choose from. Choose 1 or the other, create the game. (You can go back later and create another Game to test the other Character sheet so you can try both). From there hit Launch Game. Then take a look around at the capabilities of Roll20 within your game table. Test everything. In the JOURNALS tab create a new Character. This is where you can open/test the character sheet. In the PAGES menu you can create new maps. In the Art Library tab you can find some Free Assets to drag-and-drop onto the map page. After that you may want to form a group of players to join you and start playing. Or you may want to get some Modules. But there are not any official Star Wars FFG modules that are already in Roll20. So it would be similar to if you were running the game at your home kitchen table. You can get the modules in-print or PDF or whatever you can get, or make up the adventures. You can create maps, or buy map-packs on Roll20 Marketplace. While there are not any official Star Wars FFG map packs in Roll20 Marketplace, there are a lot of generic space adventure map packs, token packs, scenery, that you can buy and use easily.
