Get real.
You need a letter of permission signed by both parents cross the border if you are under 18. You also need passports. Canadian Border Services is also going to have questions about what you are doing in Canada, where you are staying, if you have funds for your trip, etc. and it isn't going to take your word for it. If you are underage, CBSA is going to be contacting your parents and wondering why three kids aren't in school. Even if you are of age, CBSA will want proof of residences, jobs, college records in the United States and they'll want to contact your "friend" in Canada and wonder what the heck they are doing housing three girls who they barely know. Any CBSA agent will be thinking human smuggling, prostitution, drug smuggling, or illegal workers.
I seriously doubt you'd be allowed into Canada. Even if you somehow did, CBSA would almost certainly limit the stay to only a few weeks based on your lack of incomes, jobs, school requirements, etc. At that time, if your passports aren't scanned back into the US your passports would be flagged for an overstay and your names, descriptions, and pictures would be on every police computer and a CBSA border enforcement team would be paying your friend's friend a visit. If you are actually under 18, the moment your parents phone the police... they'll see in seconds you crossed into Canada and they have Amber Alerts out in Canada flashing your pictures all over the news, highway signs, etc.
There is no one in Canada who can help you. Canada enforces its immigration rules through social systems. Non-lawful residents can not attend school, work, or look for work in Canada. Nor can they obtain driver's licenses, social insurance numbers, health care, enroll in school, open bank accounts, etc. $2,000 wouldn't last a month for three people in Canada. Working in Canada illegally is pretty much impossible. You require a valid social insurance number and this is verified with Canada Revenue Agency and Citizenship and Immigration Canada before your first pay check. Companies in Canada don't hire illegal workers as in the United States. Nor can you possibly rent a place in Canada as a minor or without Canadian ID and a bank account. Other than working as prostitutes or something otherwise illegal... this isn't going to happen.
Nor can any friend seriously put up three girls in Canada. You'd go through $1000 a month in food alone in most cities. It would be illegal for him to house illegal workers, those in the country illegally, or runaways (extremely serious in Canada). One should be asking themselves what kind of person is willing to allow illegal minor girls into their home and risk years in jail?
It's also almost winter in most of Canada. If you are minors... I'd give you a 1 in 100 chance or less of making it across the border, and, if you make it, about three days for an Amber Alert or CBSA/RCMP to be busting down your friend's door. If you are 18 and over... about a month or two before you run through that money, realize that you can't live (work, rent, drive, etc.) in Canada without lawful residency, and end up leaving Canada by yourselves to avoid freezing to death -- baring maybe prostitution.
They won't let you in with no ID and $2000 won't last month for 3 people in Canada.
what should you bring? I say bring condoms cause the only way you'll be making money and banging johns.
Tip #1. Forget the silly idea. You'll never even get across the border if you're under 18. In the unlikely event that you do get across the border, you won't be able to get a job, you won't have access to any government services, you won't have access to health insurance. How do you expect to survive?
Who, hahahaha you have made my day. we will stop you at the boarder, walk you across to the US boarder control boys, and they will hand you over to state troopers.
This is stupid.
