You don't need to spend much money on a DIY light kit, and that would really help.
Personally, I think good camera work is the first thing a new filmmaker should learn. How you choose to frame your shots, and where you put your camera are extremely important.
Watching your video made me think of the very first assignment I received in the lone filmmaking class I've ever taken. Our assignment was to shoot 1-minute of continuous action. Not action, as in fighting and shooting, necessarily, but anything that is continuous, and all in one location. As an example, my assignment showed a pair of dudes arguing over the last slice of pizza, before playing a game of rock-paper-scissors.
I think you could benefit by stepping back a bit, and undertaking a similar project. There's too much stuff going on in your video, and I'm afraid the action is a bit unintelligible. Watching your video, I often couldn't really tell what was going on, and where. Perhaps, for your next video, if you want to stick with gunplay and stuff, cuz it appears you're having fun with that -- perhaps you should pick a single protagonist, and keep him on camera at all times. He doesn't need to be the focus of attention in every single shot, but he should be in every single shot (even if it's just over his shoulder, to look at the villain). That way, you could practice the ability to keep the narrative (and yes, even a gunfight has a narrative) more cohesive and recognizeable, instead of just a bunch of seemingly random shooting. This would also be a terrific way for you to work on the basics of filmmaking (like the 180-rule, and the 30-degree rule).
Good luck on your next project. You're having fun, and that's what's most important. But you know what? Producing quality films is even more fun, so don't be afraid to step up your game and take a little more time to improve the quality of your work. Cheers!
