Hi Amy,
This is a great question that I am sure many people ask. I definitely asked it to myself at one point. There are so many ways to turn $20K into $100K, but first a quick PSA:
Goal Setting: Focus your awareness on the reality you want to create and the opportunities to create that reality will become visible. You dictate the (realistic) timeline in which you achieve your goals. Write them down, put them in front of you, and focus all of your energy on them.
I have 45 units that I have acquired in the last 3 years, and I plan on buying another 50 in the next 18 months. Here is what I do:
1) Find a deal that resembles your model. Lock it up with a $500-$1,000 EMD. Perhaps it is a single family 4 bedroom with a $200K After Repair Value on the market for $100K.
2) Find an equity investor who will go 5x in with you capital for 70% of the deals together. This investor should have a credit score above a 720.
3) Take your combined $120K to a hard money lender who will give you a credit line at 12-16% of $480K. Try any of the hard money lenders on Bigger Pockets for your state. The credit score becomes important here. Now you have $600K. Only $20K of it is yours, but now you have something to invest with.
4) Buy only great deals. If you buy too high or too risky, you can get stuck with a loan charging you 12-16% and a house worth less than you paid for it. But if you buy correctly, you will have a house worth way more than purchase price for a small cost of capital.
5) Fix & Flip OR Cash Out ReFi - you don't want to hold on to the debt for very long because the interest is expensive. So either sell the house for a pretty profit, or refinance the property to get the cash out to payback the hard money. You can find exit lenders that will do cash out ReFi's in as little as 3 months after purchase. So you only have to pay 3 months of hard money interest before you refinance for a conventionally structured mortgage.
6) Now you own a house and its respective rental income OR you have a profit from the flip and you are square with your hard money lender. They are happy with the loan experience as is your equity investor, so everyone agrees that you should take the $600K and do it again.
7) Repeat as many times as necessary until you have reached your goals.
8) Be cautious of market trends and unexpected downturns to avoid purchasing high and being under water with a project.
Good Luck and Happy Hunting
Ben