That was a fair price for the machine you got, but it was not a bargain. What you are describing is not normal, even for a single right foot. You will need to buy a presser foot and a welt foot for your machine. You can't sew everything with a zipper foot, also called a single right foot. I'm surprised that the guy you bought the machine from didn't have other feet. The pictures show a welt foot, a presser foot and a single right foot from left to right. These fit my Consew, but other than how they're connected to the machine they are the same. Here is a link to a presser foot for your machine. http://www.ebay.com/itm/Adler-Walkin...item5d33f55936
1/4" is the most common size welt foot used. This price is high, you can get these from Cut Sew Services a lot cheaper, but their web site is really hard to navigate. I changed the title of your thread to include "Adler 67 questions", so more people would look at your questions.