Q: Just got an iPad Mini: What do I do now?

The link below is a year or two old but it gives you the basics on how to set up your iPad. If you're not sure how to do it take your mini to the Apple Store and they'll help you.

http://ipad.about.com/od/iPad-Tutorials/ss/How-To-Set-Up-An-iPad-For-First-Time- Use.htm

Setup as new.

Settings>General>Reset>Erase all content and settings

If you don't already have one you'll need to make an Apple ID to set it up.

http://www.apple.com/support/appleid/

Pay attention to setting it up. You will either need to provide a credit card or follow the instructions to make one without a credit card (that's what I do, I just buy and use an iTunes gift card and don't use a credit card)

http://www.apple.com/support/ipad/

There is also all sorts of info and step by steps here.

In addition you might look through these articles for more information...

http://www.apple.com/support/ipad/

This Apple paper might help too.

Get started with iPhone, iPad, and iPod touch - Apple Support

You're welcome.  Give us a idea of what you lke to do and I'm sure we can suggest an app to help you do it.

ICloud is just for backing up what's on your iPad, delete it from your iPad and it's deleted from your iCloud backup. To store photos and PDFs  you can get the DropBox app and a free DropBox account.

You're welcome.  Unfortunately having never owed an Android device I can't really answer your question, sorry.

Another question I can't answer. I don't have a computer  so  I have no idea how you would stream music from the Mac mini to the iPad mini. I think you might have to start a new thread with your various new questions.