i dont have shit to do at work
But think of what that does for your hourly rate!
more so I have no clue about databases / ways to store the data and also servers and how to access them
Well this is going to be something of a steep learning curve then. I would go for a web application if I were you - so the mobile devices would have only a browser installed and all your work would go on a web server.
You can either find a domain name from somewhere (there are ways to get free ones like www.srgjames.javaprogrammingforums.com
) and sign up for some free PHP + MySQL webhosting (there is a lot of it about), or you can pay for Java hosting, or to start in the basement, you can find an old server from somewhere, install some flavour of Linux (I prefer Ubuntu) on it and then install a web server / PHP / MySQL or one of the Java web servers on top of that. That way you'd develop on your local network until you have something you wouldn't mind people seeing.
Everyone uses PHP because even someone who slips and falls awkwardly on their keyboard runs a risk of accidentally generating some PHP code that will produce a nice web page. Java Web Servers are not that easy.