I think I have got it. I used to have a similar model.
Go to P. 75 in your user manual. It is called "Continuous Shooting". Go to the symbol that is a stack of images with "AF" written over it. That is continuous shooting with autofocus.
Does that do it?
You will really need to upgrade to get them "milleseconds apart" The 7D can shoot about 7 frames per second IN THE RIGHT LIGHT. The 1D2 & 2n can do 8 FPS, & I think the 1D3 can do 10 FPS like the 1D4 does, & the fastest Canon is the 1Dx at 12 FPS. For milleseconds apart you'll need video. You're also going to need a lens with a fast AF if you want top quality results.
EDITED TO ADD. You may be able to speed it up by selecting AI Servo in the AF menu (if the camera has that option available) Since you've specifically mentioned shooting an air show I recommend that you read this article I wrote BUT full scale prop planes need shutter speeds UNDER 1/320 & lower is better if you can pan well enough.