@JasmineWorthen This sounds like you are assigning the assignments to everyone instead of the group or section that it applies to. In the "Assign To" field, you can determine who needs to complete the assignment. If a student (or group of students) is not included in the assign to area then they will be greyed out in the gradebook, you won't be able to enter anything, and if this is the case, then that assignment is not included in their points. You can also put "EX" in as the grade and this exempts from those points.
Here are the steps for assigning an assignment to an individual student but it is the same for a section as well:
How do I assign an assignment to an individual stu... - Instructure Community
Hope this helps!
-Nick