Hello, and welcome!
I understand why you are confused - this is the most complicated of English verbs, and all my students have trouble with some part of it!
First, yes be is a verb, and here are the basic forms:
Infinitive following main verb:
||am, is, are
When she dies she wants to be cremated, not buried.Base form following modal verb had to:
The diagrams are to be included in his record book. [This has future meaning.]
The inflation rate is now reckoned to be ten percent.
A whole day's work had to be redone.
I hope this helps!