New to ALL this!

pick up some plastic storage bins. You can get little assorted packages pretty cheap. I use them to hold paint bottles, brushes, other assorted tools and to keep pieces organized while I build. The ones I have fit nicely into file trays, which helps clear some clutter as well.

I would add some sanding sticks to a minimum list of tools.

As others have mentioned, your tools will build up with time spent with the hobby.

Buying an airbrush was one of the best things I did, but as Don says, it will take some practice.  I was able to get reasonable results (just single colors) pretty quickly, but be prepared to experiment, whether you do it on your kits or on something else.

Roger that, Don.  

This is not something that happens suddenly.  I have amassed a great collection of tools and materials over the last 50 years I have been enjoying this hobby, and I still learn something new every day on this forum.  It's all about trial and experience over a long time.  Start with simple things and gradually work up to more advanced models.

I will specifically mention about the airbrush- using it requires practice.  Do not buy a setup and then make its first use on a good kit.  I'd recommend between half an hour and an hour of practice on scrap before aiming it at a model.  You need to find out what thinning ratios, pressures, distance between brush and tip work for you.  An airbrush is not a spray gun- it is more like an extremely soft paint brush.

In addition to tools, consider supplies to have on hand. I use LOTS of paper towels.  I keep a supply of toothpicks handy, a supply of fine sandpaper.  I keep a supply of disposable small glasses near the workbench to hold water for decal work.  Glues/cements are important- could be a topic of a whole thread. I keep several kinds handy.

As far as acquiring skills, one of best suggestions (besides practice) is to join a local club and see what shows up at "show and tell" and local contests.

As far as tools,some basics are:

Paint Brushes

X-Acto knife

Clamps

Masking tape

Glues,Quick bonding + liquid

paints

tweezers

sprue cutters

magnifier

An airbrush I would recommend would be the Badger 150,very easy to learn,if I could you could.I use a Model 121TK compressor from Airbrush City.

Also look into Basic Technique modeling books,Kalmbach offers quite a few available right here on this site,or you can explore Amazon and see what you come up with.

Surf the forums and ask questons,most everyone will answer up with some knowlege,and mosy of all have fun.

Anthony