The best calls are the ones you can make sound like a turkey. Easiest call to learn are generally the friction calls. I like the Quaker Boy Grand Old Master Box Call, H.S. Strut slate over glass or their littl Duece with a couple different strikers. A push button call is pretty easy to use. A crow call or owl hooter is good to have for locating birds.

Diaphrams are tougher to use. First you gotto get past the gag reflex thing. Then learn to keep it in a good position to make turkey sounds. For me the easier one to use was a Lohman #820. It didn't slide around in my mouth like many of the others did. The reeds were thin and easy to blow. I've since added many different diaphrams to my arsenal but I always have one of those Lohman #820 along for old time sake.

Best of Luck!