Nearly all of your questions have been answered on this thread, so I would take the time to read all 42 pages (really!). This thread is PACKED full of information, free template links, and the like. A favorite free site of mine is
http://www.shabbyprincess.com. There are others but this has a GREAT sampling for beginners.
But even better, I would go out to CM's website, click on Help, click on Digital, and then Storybook and you will find a TON of webinars that will walk you through the most basic of skills with the software to the coolest and creative. The training is AWESOME! And the best part, you can pause it, rewind and watch again (super for busy moms like me!). MOST of your questions will be answered in the training including .png files, etc.
As far as printing, yes, you can print anywhere. Again, read through this entire thread and you will find out where most print - many save each page as a .jpg and upload to shutterfly and create their own album cover on their site. It is definitely more economical but there are rumors they use a glued binding instead of the super tough CM sewn binding (more likely to stand up to the book being enjoyed over and over - and isn't that the point?).
Rest assured you have made an incredible investment. I am head over heals in love with SBC+ and haven't regretted my purchase for a second. I am whipping out pages faster than I can take photos (poor me, I know).
Do take time to read through the long thread - you will find answers to questions you didn't know you had, learn some cool tricks, and find links to great free templates (which I live by).
Also, pay attention to the webinars. My latest favorite thing (and this will make more sense after you start using the software some): Okay, so let's say I have 3 photos for a page and there is a free template from CM I downloaded that has the layout I want but it doesn't use paper that I want for this page. Easy: unlock the back page, and element by element assign what I want to use instead. I've turned baby boy pastel pages into bright school pages using free paper from other sites. The best part is the layout was done - I simply substituted.
Another thing I have taken time to do: use a scrapbook catalog and create templates of their layouts in shades of grey, save in a separate album/project. I can then import the templates later, sub in my paper, photos and embellishments and be nearly finished in no time flat.
Good luck and have fun! Read this thread and watch those webinars. You won't regret a minute of the time spent.