You could go for a minimalist style since you are starting with a bit of a blank slate anyway. To achieve a minimalist look, keep the bed simple, but go for one large art piece that will add a pop of color to the white walls. For a DIY art piece, you can find an inexpensive picture frame and use it to frame some used fabric, such as a pretty sheet. Both the fabric and the frame can be found at most thrift stores. You will need a glue gun or staples to secure the fabric to the frame. Down below you will find a video that gives you a general idea of how to do it. Add an accent pillow to the bed or a lamp in a coordinating color and you are all set.
Minimalist color schemes often include white walls so that should work well with your bedroom. Sometimes, one wall is painted for contrast. Here is an article that explains how the minimalist interiors utilize color.
The key is to stick to only one or two shades per room and keep accessories to a minimum for an uncomplicated look. I hope that is helpful to you - enjoy decorating your new bedroom!