Question

how learn develop game in windows phone
first step

Answer 1

You should learn C#

Answer 2

i know that c #
and develop on windows phone apps
but need to learn how make game

Answer 3

Multi-threading is your friend. The development needed depends on the type of game. Storyline games are very different from action, etc.

Answer 4

Try learning XNA or Unity. I find Unity better as it supports multiple platforms.