re: "Please have customer support contact me regarding setting up my profile."
It is entirely possibly that nobody is going to contact you unless you can explain what your question is.
Can you tell us what your question is?
re: "I saw a job posted on UpWork for a Registered Dietitian to review a menu at a school that I would like to apply to. My question is what category of work would I set up my profile under for this type of work? None of the categories really fit this."
When you have completed setting up your freelancer profile, then it will not matter what category you are in. You will be able to apply to any job on Upwork.