Campaign structure questions

By Bebador, in Imperial Assault Rules Questions

Hi, just bought the game and im reading the instructions so we can play the 1st campaign with friends. After reading the guide, watching yt tutorials and this forum Im unsure about the rules of the campaign structure:

1) I dont understand the story mission cards. The next story mission is dictated by the outcome of the previous one, do players get to choose different?

2) when you draw 2 cards from the side mission deck, rebel players decide which mission to play. But what happens to the side mission not chosen? Is it removed from the game? Put back in the deck and re shuffled?

3) i just have the core set, how should i read the time period of the side missions?

4) The upgrade/buy phase is after any mission type right (story/side/forced)?

5) there are 2 side missions together and then a final side after story 3. After story 3, you draw 1 or 2 cards of side missions?

thanks!!