Student or Learner
According to Merriam-Webster's, the term laid-back is an adjective and is hyphenated.
Ex: My professor is a laid-back guy.
[clearly an adjective here as it precedes a noun]
However is the position is changed:
Ex: My professor is laid-back.
If it does not precede a noun, is it still hyphenated?
According to Webster's, it should be hyphenated in all cases. Am I understanding this correctly?
Yes. It is an adjective in both cases. Predicate adjective in the latter.