Pfaff Help PLZ

I have my mother's Pfaff...it's old but for the most part in great shape. Problem is this...(well several) I don't have a clue how to sew so I've read the book and threaded it etc but the bottom stitch is very very tight I've adjusted the tension as well as the screw but doesn't seem to help. I'm going to try and take basic sewing lessons if I can find someone that will teach them. I had classes set up at Jo-Ann's but the instructor was very unorganized and canceled on me several times before I finally asked for a refund for the class. I've looked in my local phone book and can't find a Pfaff dealer or someone who is listed to service them. Since it's this old do you think just a generic sewing machine service person would be fine? I really think it's probably something simple and I know it needs to be cleaned and oiled. I realize that I could go buy a cheap replacement machine at Wal-mart but Mom loved this machine and treasured it so I'd really like to learn to use it.

Thanks