We use "had better" to refer to the present or the future, to talk about actions we think people should do or which are desirable in a specific situation. The verb form is always had, not have. We normally shorten it to ’d better in informal situations. It is followed by the infinitive

...had better (infinitive form)....

e.g. I had better go to the mall before it gets dark.

You had better leave him alone.