I bought a used Bernina from a sewing machine sales and repair shop. Bernina was coming out with a new model and people were trading up. I got lessons there. I love it! 8 years later it works like brand new. However, it is heavy. Since I go to Sit & Sew and a quilting Lock In Nite and other quilting groups - I got tired of lugging it. So I bought a Singer Featherweight. It was made in the 1940's. I bought it at my "home" quilt shop. The owners get them from E-bay and fix them up before selling them. They also showed me how to use it. Now I carry the Featherweight when I go out and use the Bernina at home. I tested to be sure both machines were sewing the same 1/4 inch for seams.
Choosing a machine takes time. I think they each have different pros and cons. When I was beginning, I just wanted one that would go backwards and forwards. I didn't know about self threading and bobbin warnings, etc. You can't miss what you never had. I would start with something simple and trade up as your skills improve.