:You guessed right above: to do something and then "go from there" means to start out doing something, and then continue on in the direction that that leads you. PAR is encouraging you to start out by editing the article to the way you think it should be, and then see what happens and continue from there. He doesn't say it, but I'm guessing he has in mind that other editors will probably jump in and change what you wrote, so you'll want to try to work with them and arrive at a compromise. His message is not at all unkind, and in fact was meant as encouragement for you to edit the article.