>>If you have to perform rescue breathing to a victim who has a broken neck and your by yourself the book I was reading said to safety pin the victims tough to their lip to keep it from blocking the air way

Oh, god, scout, don't even think that, it makes me cringe. Far better to take a proper CPR course and learn how to do a jaw thrust without head tilt, or carry a cheap pocket mask (I have one from Saint John Ambulance that's 2" x 2" x 1" and clips on my keyring.)

If you absolutely have to leave the casualty to go for help, that's a different matter; but in that case, you shouldn't leave them on their back anyway, you should roll them over (even with a head injury) in case they vomit and choke.

I cannot conceive of a situation where you would need to safety-pin a casualty's tongue to their lip, ever. What happens if the casualty regains consciousness? Do you really want to try maintaining C-spine on a casualty who's convulsing with pain because of something you did?

Don't even think about it. Get a proper First Aid book, or better yet, take a Red Cross or equivalent course.