We love questions here so don't worry about asking. We all were at a point of not knowing at one time. I have learned everything I know from asking questions here of members at BPT's.
The green bridge can not be made into a double wide only above and below. The red bridge is made to be either a single wide or double wide. Its just moving to two top pieces and the one bottom piece in a different direction and they just snap on and off. You will need double wide yellow risers if you go with the double wide option.