There are some differences between vintage patterns and modern. I've sewn a bit with vintage and often the instructions are sparser than in a modern pattern. If you want to try something simpler first, but not pajama bottoms, look for the "It's So Easy" patterns by Simplicity. They are easy and the instructions tend to be well-written. There are some dresses that are sort of vintage style. Also go to the library and check out a book such as Vogue Sewing or Simplicity's Simply the Best Sewing Book. They explain step-by-step things like putting in zippers, adding pockets, etc and are just really great references for basic sewing things. Actually sometimes thrift stores have older copies of the Simplicity sewing books for very cheap: the outfits look crazy, but the information is still good.