My thought is that there are no warranties off Craigs list. With a new one, even an inexpensive one you can often take a few free classes.
If a home ec teacher can take a group of 6th-7th graders and teach then to sew then I think an adult could take an instruction book and make her way through the basics.
When you do get a machine practice sewing using my trick.
Take a regular piece of notebook paper and "sew" it, no thread, down the lines. This will get you used to the feel of the action of the machine, how it pulls the fabric to sew it, you do not need to pull it or push the fabric btw, it will help you get the feel of how much pressure to put on the foot, racing it or going to slow won't hurt anything, etc....it helps you get familiar and used to the machine without ruining anything.
I think there are some very easy basic patterns out there. Ask the ladies at Hobby Lobby in the fabrics department if they would help you with the pattern. Take out the instructions and read them while you are in the store, I often do this to see if there is anything else I need to buy.
If all else fails find a local quilters group and find out if you can come to a couple of their meetings, make a few friends, quilters sew well.