Hi Nicholas,
if you want to do some game related art, then you should focus on a single game art direction first. Either 3d art, because it is still the most common art direction in (non casual) game development , or 2d art, which is still used very often in casual/indie projects.
Art skills can be subdivided in tool knowledge and art specific skills, much like coding (you need to learn a language and you need to learn about certain algorithm, methods, paradigm etc.).
2d art:
If you go for 2d art you can use photoshop ($$), gimp(free) or any other useful paint tool.
Primary skills are drawing and painting.
3d art:
If you go for the 3d art , you should look at blender (free). 3d art is much more extensive. Skills you can learn:
- modelling
- sculpting
- rigging
- animating
- texturing (->painting)
You best start with modelling, because it is the core element of 3d game related art. Everything else is optional.
Be patient, art, much like coding, needs a lot practise and don't get confused by others who say, that other tools , like maya/max etc. are better. They will not magically improve your skills (a bad workman blames his tools...), it will just speed up your workflow when you are limited by other tools. But this will most likely take some time