the majority of games will require 3d models and textures to be made outside of the unreal engine. Most of the tools you are likely to need are free and open source. Blender, krita, inkscape, crazybumb ect.
The only paid program that doesn’t have a good free alternative and is very useful is substance painter.
It terms of hardware that you may need (or may be helpful) depending on what you’re doing. A decent computer for sculpting 3d assets, a mic and electric keyboard to make sound effects, a camera to make textures for realistic games, vr headset, playstation, xbox for testing on those platforms.
Various other software:
NVIDIA GameWorks, flowmap painter http://teckartist.com/?page_id=107, github/sourcetree(for sourcecontrol), artstation account (for showing off your work), audacity, freesound.org.
Voice acting and music composition may require hiring people.
Then you should market your game, which will require working with various outside programs, facebook, youtube, reddit ect.
When you publish the game you’ll have to put it on steam and like outlets. might have to figure out how to make cds.