Be careful about shopping at Goodwill. I can't speak for all Goodwill thrift stores, but around here they over price many of their household goods. Sometimes you'll even find a better deal buying an item brand new! It helps to have a phone with internet access, so you can check the going rate of an item.
Besides thrift stores and garage sales, we used the app called "Offer Up". It's similar to Craigslist, but a lot more user friendly. People who use Offer Up (At least where we live) tend to be quick at responding. We've also experienced fewer scammers through Offer Up as compared to Craigslist.
As a side note, be very careful when buying used furniture; Bed bugs, cockroaches, urine and smoke are a few of the yuckies you could run into; so check an item very carefully before you buy. Thankfully, the worst problem we had was a bunch of sunflower seeds in the bottom of a couch... We cleaned them out immediately as there are plenty of critters that could be attracted to seeds.
Not everyone prefers to buy used, and that's okay too, but you'll need a much larger budget just starting out. The combined total of the furniture in our fully furnished apartment amounts to under $200. For us, that's worth it not to have the most stylish home. The Lord provided for us in so many ways! Just about each piece of furniture has a story of God's provision attached to it. I love to look around our house and be surrounded by the goodness of God.
Jake and I enjoyed bargain shopping before and after the wedding- it's a great bonding experience :) May you also enjoy filling your home with good things!