Find TDC. While easy...it's not as as obvious as it seems. Flywheel marks on VW's can be off significantly.

Pull a spark plug (it doesn't matter which one), rotate the motor someplace close to where you think TDC is. Stick something stiff and unbreakable down the spark plug hole (an unbent coat hanger works great) and SLOWLY rotate the motor while holding the coat hanger, with your hand on the head/engine block. When you feel the piston "top out", rock the crank back and forth a few times to make sure you're in the right spot, then check the TDC timing mark on the flywheel. It should (ha!) be right on the timing mark. If not, make a new mark with a small paint brush, in a color you can easily distinguish with a timing light (white, yellow, red).

Old British motorcycle trick to find TDC - machine the center out of an old spark plug, tap it and insert a threaded rod, with nut at the top. Insert it and adjust it so stops the piston about 10-20 degrees before where you think TDC might be. Go one way, then the other...halfway between the two is TDC...but you really need a degree wheel to mark it. Norton/BSA/Triumph mechanics call it a "piston stop".

But I digress...

With #1 cyl. at TDC, the notch/dimple on the cam sprocket should be just AT or BELOW the flange at the front of the valve cover. Each tooth on the cam sprocket = 8-9 degrees, so don't get off a whole tooth. If you want to play with cam timing, try an offset cam "key", which you can make if you're patient with a file, or you can buy with Mastercard or Visa.

Also...do you trust your timing light ? If you say "what's a timing light ?", we have a larger problem. Make sure you use a timing light with an adjustable "advance" knob on it, so you can see just how much advance you're running at 3500-4000 rpm.