The short answer is no – you don’t need to wax it before riding. If you just bought a brand new board and want to ride it right away, go for it.
New boards do come with a wax, though it is generally going to be what is called a machine or factory wax.
The machine wax process is a quick and easy one. The board is pushed over a heated wax roller which applies wax to the base of the board, then the board is pushed over a second roller that buffs any excess wax off the board, and gives is a polished look.
The machine wax doesn’t get the base overly hot, or put much wax on, which means that it is only a thin layer of wax that gets added to the base of the board. This means that the wax won’t last too long, but it will give you enough for a couple of days of riding.
If you have the time, and a board with a sintered base it is always a good idea to give it a proper hot wax with an iron. The iron wax will do a much better job of getting wax into the base material, and will last a longer time than the machine wax.
If you are going to be riding regularly, get your set a simple waxing kit and learn to do it all yourself.