How do you time the ignition on a Honda. I can't find the timing marks,

There's a small "pin" on the timing belt cover just above the crankshaft pulley. Also, there is a white mark on the crankshaft pulley. When those align, then the marks on the camshaft sprocket(s) should follow the line where the head meets the block. Try wiping the crankshaft pulley a bit if you do not see the mark.