An airbrush and compressor are an expense and my experience has been buy cheap buy twice, however I’ve seen reports of many people happy with the AS186 set (just over £100 on Amazon), which includes 2 airbrushes. If you’re painting in a garage, you’ll need a moisture trap and at this time of year you’ll need two, one on the compressor and one on the brush.
As to paints, just get them as and when. My preference is gunze or tamiya thinned with gunze levelling thinner. Whatever kit you are doing you’ll always need a new colour.
Basic airbrushing is fairly straight forward, so you should get a better result than brushing with your first attempt. More subtle techniques will come with practice.