Walk down Main Street towards Cinderella Castle. Just before you walk over a little bridge, you will see a sidewalk path to your left. Make that left and follow the sidewalk. Ahead of you on the left is Crystal Palace. You can see Crystal palace from Main Street.
If you are standing on the Crystal Palace front steps, you will see Cinderella Castle.
CP is very easy to find. The hub, by the way, is the round area directly in front of Cinderella Castle. It is referred to as a hub because it has many spokes coming off it, such as Main Street and the roads to Adventureland, Liberty Square, tomorrowland, etc.