Without prior knowledge of 2D/3D there's little hope of adapting what you see on one program to another. You should have the basic knowledge on the topic and one of the software to be able to follow tutorials on another program.
IMO when you can't afford Photoshop and Maya (which are totally unreasonably priced for individual learning outside schools that offer student licences) you shouldn't really pay for courses like that either. I wouldn't trust the reviews they have posted there blindfolded. "I got employed by EA" "I made an XBOX 360 game". It is misleading to imply that buying something for 49$ is going to yield you such results. It takes huge amount of time to learn how video games work, how you make them and how you make individual assets for them. Whether you pay 49$ or not doesn't matter, it just takes patience and dedication.
It doesn't matter much which software you use for learning. The free alternatives won't bottleneck the process, these days internet is full of resources to learn the exact thing you want to, for free. Unless you aim to get employed by the giant companies in the field you don't ever have to use Photoshop or Maya to make great games.
So what are you into most? Modeling, textures, game development? You can literally go to YouTube and search "my first 3d character" or "my first blender game" tutorial and get results in hours. That will build you a foundation you can use to build up your knowledge and refine your skills as you go.