To be is a verb and it means to exist, or describes a state of existence. It is the most common verb in English.
Conjugation:
I am
You are
It is
We are
They are
Past participle = been.
I have been to France =/ I have travelled to France.
I have been sad all day = My emotional state all day today is sad.
Be is also used as an auxiliary verb. Auxiliary verbs are helper verbs, they don't have a meaning on their own, but they are used for the construction of certain verb tenses.
I am going to Paris. I am (in this moment or in the future) going to Paris.
I have been going to Paris often. Recently, or over the period of my life, I find myself in Paris often.
He is going to Paris. He is (in this moment or in the future) going to Paris.
Present perfect continuous:
I have been waiting for 5 minutes.
Been is the auxiliary in this case, it doesn't have a specific meaning. It exists to construct the present perfect continuous tense. This tense describes something that began in the past and continues up until now. The person started waiting 5 minutes ago, and they are still waiting.
I hope this clarifies something for you.