No, as a verb, 'need' is not a linking verb. A linking verb 'links' the subject to the object; in other words, the object is some form of the subject, not something different. For example, 'Mary is...
It's a linking verb Action verb express a action of some kind. Linking verb express some state of being
Action bro.
The verb is 'act' (acts, acting, acted).
Yes, a verb indicates an action or state