Will citing references incorrectly, in my dissertation, negatively affect my grade? and what if I forget to cite a few references? Please let me know.

How do you mean citing incorrectly?, if you are following a standard format, then you should be fine

If you have acess to a ref manager like endnote it make sit much easier

missing out a reference, I don't know how you can do this unless you have been told references must be used - which would be unusual

either way these would most likely be minore corrections in formatting

Not citing references means you plagiarized your dissertation. Citing references incorrectly in also a very bad practice. You have to be very careful with citations. Writing a dissertation is the most important and difficult part of your degree program, so you can very well understand its important. For in-depth knowledge on citation and how you can plagiarize your work, I suggest you visit the following blog: