This is a must have if you want to airbrush - I have the same kit and the key is to always clean after every session or between colors - I usually run thinner, then windshield washer fluid (or windex original - with ammonia), and water (repeat until the airbrush spews clear) - no need to buy specific airbrush cleaner solutions
If your compressor doesn't turn on when you plug it in, you need to increase the pressure (lift and twist the black knob and turn towards the plus sign - 25-30psi will be fine)
A lot of people use Citadel but I'm more used to Tamiya but the concept is the same - thin paints (in general 1:1 paint:thinner) prior to airbrushing
I would stick to the dual-action guns over the single-action in that kit since the former has more utility and control - I haven't found a use for single-action yet but I'm sure there is - all you need to know is pushing down the trigger controls air flow while pulling up on the trigger controls how much paint comes out - practice on paper first
I've heard that using windex is a great alternative to using thinner for acrylic paints but I haven't tried yet - if so, then it's a great money saver
I would also look into a airbrush booth if you plan to paint indoors to collect the fumes - I have the generic portable one and it works great (https://www.amazon.com/Master-Airbrush-Portable-Painting-T-shirts/dp/B00BMUH8L6/ref=pd_sbs_201_1?_encoding=UTF8&pd_rd_i=B00BMUH8L6&pd_rd_r=36F6CYT7WNA7Q9Y4AVS9&pd_rd_w=18wRl&pd_rd_wg=V3l93&psc=1&refRID=36F6CYT7WNA7Q9Y4AVS9)
r/modelmakers has a great post on airbrushing if you need further help including how to and maintenance