This thing was a godsend for me.....helps during the cleaning process and gives you a place to put your airbrush when you're not using it (Besides disassembling and sticking it in the box).
For the love of god, get a respirator. I don't care, people are going to respond or retort my request saying that it's not a life or death situation to get a respirator. I. Don't. Care. If it's a matter of spending a little to make sure you don't have potential lung issues in the future, I think I'd rather take that. What's a good reason to NOT get a respirator?
Not everyone's lungs are the same, but in the end, with enough irritation, you can screw up your lungs. OneWhoGeneralises says you're working with non-toxic paints. Sure, most of the time you are. But it's labeled as non-toxic in the terms of how it is being used, and it certainly isn't non-toxic in terms of ingesting it, but it is not for inhaling it. If you want to read up on airbrushing, it's about atomzing paint into small particulates to apply to a surface. You're painting. Consider what it would look like after six months of breathing those particulates in your lungs, it would look just like the air filter in your AC system and it's time to replace it by that point.
You'll need an airbrush cleaner, Iwata has a good one. That is not non-toxic and it is very irritating to the lungs. I can attest to that. Had a day where I misplaced my respirator and tried airbrushing without it once. I ended up for three days feeling slightly short of breath.
But as for additional accessories, I suggest these at the minimum:
The pistol grip filter will be useful if you get water spitting out with the paint as well, depending on the humidity levels in your area.
The cleaning station is definitely something you should get, whether that one or some other cheaper one is fine. You just need something to vent into when cleaning or switching through colors in your airbrush. Home made may be a little dangerous, they can hold the vapors and become explosive. No personal experience here, but I got that tip from a professional airbrusher.
A nice to have when you want to get one, is an ultrasonic cleaner. It's great to disassemble the airbrush and plop it in after a session and comes out all clean. I also like to use the ultrasonic cleaner for removing paint on old figures as well.
Also! When getting an airbrush, check which one you're getting and if you're getting the compressor and hose separately, make sure you get ones with matching threads or you'll have to get a converter. Badger and Iwata have different threads, I know the Badger Krome comes with a converter to use Iwata hoses.