Be sure to use the preset manager in your current version to save all of your brushes, shapes, patterns etc as you will need to take them to the new version manually. Also, if you are the holder of a license for one of the CS versions then you can get a CreativeCloud account for $29 per month which gives you access to all their software including Illustrator , this is the plan I have as I like to try to teach myself to use the programs that I am not so familiar with.