16th Birthday??

I want to have a sixteenth birthday. My birthday is in January and i want the theme to be winter wonderland. When i searched winter wonderland online it was all christmas. Is that theme only good for December? And what type of food should be served? I'm thinking more on the appetizer side. Also, im want it to be semiformal. I want everyone to dress in white, blue, and sliver(gray) to match the theme colors. Is that asking too much? What should the invitations look like too? I've never really planned a party before so i dont really know where to start. Thanks!