Well, if your game gets kidnapped, rule #1: never pay ransomm they will kill the vicitm anyway <img src="smileys/smiley36.gif" border="0" align="middle" />
not much you can do to protect your program other then using the minifyer while exporting. construct 2 has a build in obfuscator during exports, which mangles the names and structure, making it a bit more troublesome to simply extract and read the codes.
Other then that ... nothing really. and you shouldnt worry too much about it.
As for uplaoding, you will need a google developer license, developers.google.com
When you have that you can start creating APK files and upload them to google store.
You will need to build your APK though, either with Ludei (apply for a commercial developers license at ludei) or use crosswalk.
So much info relating to this .... I suggest you read up :)