As a new member here you are not allowed to actively sell it but you can post the details of the machine looking for advice. Pictures of accessories will help as well.
Things that would help the machine experts/collectors here are of course pics of the machine, make, model, year and serial number of the machine. Value of the machine is pretty much only what someone else is willing to pay for it. Be advised that some machines, no matter what they sold for brand new, may not get much in the resale market. Also you can search E-bay for the type of sewing machine it is and you may find what some have sold for on ebay.
There seems to be a much more active market for vintage all mechanical machines as opposed to newer machines that have computers in them.