"go from there" can refer to any discussion where the details are unknown and still to be clarified. Tell me what colors you like, and we can go from there. [decide on a product or thing.] "go off something", besides the meaning of to stop taking some drug or other, means to start with a specific measurement as the first step. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.