Hi @Jacob Turner! Welcome to BP, and Congratulations on deciding to start investing in real estate. That's a great strategy you have in mind - house hacking is the best. As far as financing, the "easiest" route might be to go with a traditional bank loan, if you would qualify. This would depend on your income and credit history, and given your age I would guess it might not be an option right now, but still might be worth talking to a mortgage broker about - if for no other reason than to find out how to qualify down the line even if you can't right now.
Other options are...
Joint Venture opportunities - finding someone who has the cash, either for most or even all of the cost of the property, and is willing to put their money out up front in exchange for equity, work, etc. An example would be if you found a great deal for 150k cash lets say, and you find someone to pay for it in exchange for 50% equity in the property - and you get 50% of the equity for finding the deal. This is a simplified example, but there are infinite possibilities.
Hard Money / Private Money - These are alternative resources which are typically meant for shorter term scenarios where you need money for a certain period of time. Interest rates will often be very high relative to traditional bank loans, but that's because this is one of the last resorts when traditional bank loans won't work. Those who lend hard/private money have the leverage because you don't have a better option if you're using them.
Seller Financing - This is usually not easy but definitely not impossible to obtain, and the possibilities are endless because it comes down to what you and the seller agree to. The idea is that the sales price is X, the down payment is X, and the monthly payments are X, with a term of X. There can also be balloons involved, or deferred payments, and other stuff, but I'm just giving you an overview.
Lease-Option - There are a lot of creative ways to leverage the lease-option strategy, but the basic idea is to rent from the seller for a period of time until a certain point in the future where you'll have the option of purchasing the property. One way you could make this work is if you either lease from the landlord at full rent for a couple years until you can qualify for a loan, then buy using the loan. Another way is if you can negotiate a discounted rent so that you can make money on the spread. Obviously you're going to need a seller who is motivated in some way, for that. Example: House needs 10 grand in work to be rented and seller is broke, and can't or doesn't want to sell the property yet, so you offer to pay 10% of market rent for use of the whole property, with option to purchase after X period of time. You put in the 10 grand in work to get it rent ready, you charge full market rent, and you make the 90% spread between your negotiated rent and market rent, minus your own expenses (Another simplified example, obviously).