Here's a standard answer I've used for this question a couple times:

Material for Building

Glues: 30 minute and 5 minute epoxy, with something to mix it on and with, (old plastic lids and wooden coffee stirrers, plus small plumbers' acid brushes). Thin CA. (Not "Superglue".) You can substitute wood glue for the CA, but it adds time to the build.

Tools: XActo knife and extra number 11 blades. (Buy a box of 100, it's cheaper and you'll use them.) Razor saw; Kona or XActo. Kona is better. Steel straight edge, 18". A ruler will work but.... Sanding block and various grits of sandpaper. (80, 120, 200, 400.) Screw drivers, small and medium sizes, both flat and phillips types. Pliers, needle nose and regular. (At least one pair with side cutters for wire.) A good set of Allen or hex wrenches. (IMO, Ball drivers are a bit better if you can find a good set.) A "Dremel" type rotary tool will help a lot if you can shell out the extra dollars.

Covering tools: A sealing iron. A Trim iron will help too if you can swing both. A Heat gun made for covering. (Blow dryers don't really get hot enough.) More of those #11 blades for your XActo knife if you didn't buy the box of 100.

Check the kit (or ARF) contents. Most will have a list of extras you'll need to buy; like wheels, fuel tank (& size), fuel line, etc...

By the way. You should buy the engine and radio equipment when you get the plane. You'll need them all to finish the plane, and in some cases, you’ll need them to get started. Buy an engine on the larger size of the recommended range.