You will want to set octane selector on the zero mark and tighten the bolt down. With today's modern fuels, you won't likely ever need to touch that again.
You need to have ball on the needle with the rotor pointing at the #1 wire post on the distributor cap while the #1 cylinder is at top dead center on the compression stroke.
This should be close enough to start the engine and run well enough to check the timing with a timing light. You will be done when timing light flashes and the ball is on the needle.
To make adjustment to the timing, there is a screw on the backside of the distributor which takes a flat screwdriver. Loosen it, adjust the timing to ball on the needle, then tighten the screw. Your timing will then be set at factory specs.
