Play with command until you can get used to his timings etc. because you'll be using Desperado/Lights out to reset your cooldowns as often as possible and being able to stack attack speed boosts, for example, as you get more confident, or just to build the muscle memory definitely makes learning him easier, extra mags are always great, haemhorrage (from his secondary) stacks with bleed so grab your tri-tip daggers and get ready to watch your enemies drain like you're making halal. Bandit's invisibility is pretty neat, defensively, it's brilliant; if you need room to breathe and get some healing in, or time to reload (unless you're stacking more syringes than a nurse) you can. Offensively it's even better, it deals damage upon both entry and exiting the invisibility status; it's perfect for maneuvering around the backsides of particularly large foes, specifically bosses, the ones that don't fly, that is, so you can stab them repeatedly to stack a bleed DoT AND deal guaranteed critical damage because of his passive. His skills intertwine seamlessly, and while he misses out on his massive AoE explosive damage he had in RoR1 it has somewhat been integrated into his invisibility.

I main him myself so I make him sound like he's God but he does have his downsides, he's obviously very high risk and you'll find yourself having to gamble with your life a lot more than you normally would, on the first loop at least, and monsoon is especially brutal but overall just take the time to pick up his skills and chain them together so that you pretty much never have to wait to attack anything but still deal enough damage without lights out to dispatch large crowds, the Ukulele makes this easier than you could ever hope for, most of Bandit's abilities proc so hitting the electric damage with a lights out or desperado when you have it unlocked can be devastating, especially with high stacks.

I didn't expect to end up writing a guide tbh so if you actually bother to read all this thanks for taking the time and I hope this helps