If all data points lie in a straight line on your standard curve except for one point. should you ignore the point or shift the line to connect the points?

You should ignore the point. If you shift the line to correct the point, the other points which are already on line will be affected and this will affect the validity of your graph and the eventual result you will get when you use the standard curve to find the value of an unknown quantity. Note that, standard curves are used to find the values of unknown quantities.