Good answers above, particularly comprehensive from @nice.
I think a Python a good choice for learning, but if you want to build desktop apps and websites / web apps, JavaScript might be a better choice because it cuts across all those and is already catered for by MaidSafe: their ffi only supports JavaScript so far, and the API, safe_examples & tutorials all use JavaScript at this time. So for now there are a lot of hurdles to jump if you don’t use JavaScript, and none of them easy even for the seasoned developer.
The main downside IMO with JavaScript is that it is so widely used in so many different things, in different ways that it is a lot to get your head around. So if you just want to dabble, maybe Python once somebody has jumped those hurdles first, but until then or if you want to get your teeth into things, I’d say JavaScript. Be ready to be thoroughly confused by node, npm and a number of other things though - and ask rather than struggle on thinking this should be obvious. Generally it isn’t! 
The other fierce dragon you will need to fight early on is git/github, but with most of these things just carefully following instructions laid out by others will get you a long way, and you will pick up ever more nuggets of understanding as you go on if you persist.
For an editor I recommend Atom particularity for JavaScript but it also supports other languages very well (see post linked below for JavaScript and Atom).
One of the best ways to start is by looking at the code of others, and then trying to build and run it yourself, including uploading it to SAFEnetwork if it’s a Web App. Then making superficial changes, then an enhancement or two (reporting bugs and suggesting via github along the way), until you are ready to try something from scratch.
You will help at first by asking questions. More practical stuff will come later, first reporting bugs and suggesting changes, then maybe helping fix bugs etc. Good luck. 
Oh, and here’s that beginner’s post for JavaScript and Atom Editor: