First Wedding cake!! Scary

So last night our friend called me and asked me to do their wedding cake. I told him I would. So the wedding isn't till December so I have a little while to practice which I am so glad about. their theme is Christmas so I thought about a 3 tierd cake with red frosting or fondant with a white overlay that looks like snow, then have snow flakes that are sparkly drawn on the top and bottom tier, then on the middle tier a monogram in gold and white because their colors are red, silver, and gold. With flowers on it, the silver will be on the snowflakes. But they are coming over next week to come up with a design, I am really excited about doing the cake but also way nervous I am going to have to practice a lot, before I do their cake.