I would not buy baby furniture from other people at like garage sales or whatever because you wouldn't know if the furniture has been recalled, and they are usually not sanitized to protect your child from germs.
I'd recommend going to Walmart, Target, Babies R Us, etc.
Just use the floor, your bed, or whatever to change your baby on, don't need to waste your money on a changing table.
I'd recommend to get a portable fold-up swing instead of a big floor swing. You will save a lot of money and the portable fold-up swings will not eat up so many batteries as the floor swings.. not to mention because it's portable, you can take the baby anywhere in the house, even outside with the swing.
As for strollers and carseats, buy them fairly new/recent because there has been some recalls on previous items and you should be making sure you get the updated transportation systems.
You can ask Babies R Us or WIC office for referral to a place that will help you install the car seat properly. Many parents do not install car seats properly and it causes tragic accidents.