It depends, there are certain areas that you cant come back to.
But if youre actually asking do I need to finish all my sidequests in chapter 2 before moving on?
Then the answer is no
(extremely minor spoiler)
But it will be a while before you can finish them, I would suggest doing them now (outside few that might be a tad hard at your level).
Once you leave the big city to rescue Imoen, you're basically on a fairly linear rollercoaster ride for the next 30 or so hours, so get everything you wish to complete finished before moving on.
You can go back and complete the remaining chapter 2 quests in chapter 6 (though doing most of them is probably a good idea, it's not required), but for chapters 1, 3, 4, 5, and 7, complete the quests before continuing.