Installing/running vagrant as per instructions in beginning course

Ignore the entry for "Topic" and "Website" as I had to enter something since they are "required" but they don't pertain … As part of the php section of the course it recommends installing vagrant. Everything is fine until the command "vagrant up' gives me the error that it can't find the "box" even thought when I try to manually download it the error message says it is already there (cannot figure out where "there" is) been trying for hours to get around it but no luck …