Do you have to have a passport to get on a plane?
You only need it to travel out of the country, aka internationally, however it's always a good idea to have it with you whenever you travel by plane because you need identification + a boarding pass or plane ticket to get through security. If you need any other travel tips paticularly ones that deal with plane travel then funmail me because I've flown on an airplane practically every other weekend since I was born so I know my stuff!
You only need one if you're travelling to a foreign country. If you're staying within one country, you don't need it.
I don't think so, I think it's when your crossing a border. :)
only if you are going to a different country :)
just keep it with you just in case!