Fire extinguisher is a necessity, but don't buy the most commonly used dry-chemical type with the A-B-C rating. They use ammonium phosphate, which is corrosive to aluminum when combined with water, even high humidity. Find a dry chemical extinguisher with just the B-C rating ... they're OK around aluminum. The B-C type are harder to find and cost more.
I was unaware of this until vandals broke into our airport and several hangars, including mine. They emptied my extinguisher completely ... all over the airplane and everything in the hangar, like maybe 1/8" thick or more. Airport maintenance staff told me of the corrosion issue on A-B-C extinguishers. I then had to spend no less than 40-50 hours cleaning every speck of that stuff off the airplane, tools, toolboxes, shelves, workbench, you name it. It was horrible job.
Yes... CO2 extinguishers are fine, but if you have a fuel-based fire you'll want a good size extinguisher, and the large CO2 units are pricey.