as you have to know that the first course is the most important one, because if its crooked abit, then on the opp wall you could have problems.
Now, to calm you down a bit, your floor molding and shoe molding will take care of much of your concern BUT that first layer is still important.
Denise, laser levels are now soo cheap it would be wise of you to consider one for just this case. You could mark 1/4 or 1/2 inch from the wall and shoot that lazer down the wall and mark it for your line to later pop with chalk.
I personally like my first course to be straight regardless of the squareness or lack of in that room.
Lay that laser level down and shoot your line and mark the laser every foot or so. Then get your chalk line and line it up on all the marks then snap it. This will be the line for the first course.