Vanessa, it is very very frustrating to learn to sew on a machine that doesn't operate smoothly. I would recommend going to a sewing machine dealer and asking their advice. Tell them what you want to spend and see if they have a reconditioned GOOD machine. Often, you can get classes, a limited warranty, and support there. The shop owner will see you as an investment - they want to get you sewing and provide good service so you will return to them when you are ready to upgrade.
I think it's much better to get a good used machine than a cheap new one.