This is easy.

1. Wooley Bugger
2. Clouser Minnow
3. Pheasant Tail or Hare's Ear Nympth
4. Elk Hair Caddis
5. Adams Wulf

Thes 5 flies will catch anything that swims in freshwater, anywhere, and teach you the basic techniques for different types of flies so you can apply them to more complicated patterns later on.