Perhaps for now it would be best not to focus on what you want to create, but what you can create.
If your just starting out then its important to keep in mind that your desires will outstrip your abilities for while. For now focus on one or two core aspects, perhaps think about investing in the UE4 subscription and buying Photoshop (or Gimp if you want free) and working on simple 2d or simple 3d (Blender for free, Maya LT for reasonable or Maya\3DS super full pockets) games until you’ve learnt the fundamental skills required to move onto bigger and better things.
As far as software goes, use the free stuff (or cheap stuff) while you can. Buying a lot of software is a serious investment that may have little or no benefit to you at this stage in your career. Software isn’t going to magically going to make you better at producing models, games or textures just like no matter what paints you buy you’ll only be able to produce good paintings if you’ve developed the skill sets and understanding required to use them.
If you start small and aim to continually improve yourself with every project or asset you produce while keeping an eye on your eventual cool impossible then you’ll be set on the path of achieving great things.
Trying to better a Triple-A title on your first go out the gates is dooming yourself to frustration and burn out.