You've got decoys, but no call....?........ I think you got your priorities out of whack on that one, but you still have time. My season opens on Saturday. I don't know how much time you have got to practice but here is some basic observations.

1.) Most $20 calls are capable of sounding attractive enough to call in a bird.
2.) Mouth calls are versatile, cheap, and effective, ...but require a LOT of practice and meticulous maintenance to last through the season.
3.) Box calls are pretty easy to learn, but require more movement and often both hands to operate and do require some maintenance. The best are also the most expensive in the business.
4.) Pot type friction calls are easier to maintain than a box, but are a little tougher to learn how to play. However, I purrs and clucks are hard to beat on a slate. Probably your best bet if you are a beginner on a budget and want to use it next year.

Now, what is most important is to geta mentor who can teach you how to play your new instrument. When I got a tenor sax in highschool, I thought I sounded great, until I heard somebody who really knew how to play. He helped me learn to play the sax. Apply the same logic to your chosen instrument and don't be shy to ask questions. It is much easier to learn from a turkey hunter than the turkey.

Happy Hunting and God bless.