Hi Carol. Welcome to the forum. There’s some info on the Listener Crossword site about tackling number puzzles
https://www.listenercrossword.com/PDF/mcross1.pdf
The instructions (known as the preamble) need to be read a number of times to give you time to process all of its component parts and nuances. The preamble often seems impenetrable initially but it will begin to unfold. Once you’ve begun to solve, the preamble becomes clearer with every further reread.
If you’re ever totally flummoxed by anything in the instructions, the friendly folk on this forum will always be happy to help.
Good luck.