So you want to develop games but you aren't really sure where to start. The good news is that game development tools are getting cheaper and more accessible all the time. Unity 5 and Unreal 4 for instance, both are brand new engines that are completely free for people to play around in and even develop for to a certain extent. The only issue: not much content to work with. It's not a huge problem, sometimes it's a really good thing to see what you can accomplish with limited tools. First of all, it should force you to learn to seek out information which is an invaluable skill by itself. Second, this is how gaming started: people who worked with the limited technology of the time to create games that frankly we still love to this day. Limited technology or resources really shouldn't stop you from learning to do something that you really want to learn how to do.
However, there is another meaningful step you can take before you even get into Unity or Unreal; you can make mods. There are quite a few games these days that will often include robust tools that you can use to modify the game anyway that you could possibly want. One of the huge perks to working in those tools is that you have all the assets from the game that is played with those tools. Skyrim has The Creation Kit, The Witcher 2 has The REDKit, Little Big Planet is literally a game built entirely around the idea of user created content. By giving you all the assets you need to create your own levels, characters, and more it removes a huge burden from you as a developer. The downside to these kinds of tools is that they could potentially be a little restricting. Since they're tools made with specific games in mind they tend to be geared towards creating content of a similar kind to what the game had been. This isn't to say you can't make something else. It just tends to be more difficult.
The other huge perk: an audience to show your mod too. The tools these days usually also provide easy ways to make your content then available to the entire community playing the game! As frightening as it might be you will NEVER improve unless you listen to criticism. Absolutely no one is so good that there's nothing that can be improved about their work. People always try to come up with excuses like "my stuff isn't good enough" or "no one would want to play anything I make" or whatever else but here are a couple things to consider: 1. If it's the first one, you will only improve by putting yourself out there and getting experience. 2. If you believe the second one at all, then you have only two choices in front of you which are to either realize you are wrong or give up trying to be a developer. Making stuff for other people to play is entirely the point of being a developer. Put yourself out there, you never know what you'll find out.