CocoonJS is not an official export option since its support was dropped last year.
The tutorial mentioned by vendara is an official way, but indeed requires a licensed version of Construct2 to work.
In your case, it sounds like you need to export as a HTML5 website, host it online (through a file service like dropbox or google drive) and then go to that URL with a Chrome for Android from your phone.
This is the equivalent of the export option for Android since it's wrapping a chrome browser to execute your game.
Also, to export to Android you need a Construct 2 license, so perhaps are you targeting the wrong device anyway since you can't buy it according to what you say.