What part of a speech states or tells what the subject is are does or has done in a sentence?

This is the predicate. A simple two-Word example: "It rained."

"It" is the subject, "rained" is a verb, and it is the predicate.

"It is cold outside." "It" is the subject, while "is " is the predicate: the rest of the Words are modifiers.

About the subject

The main thing being talked about in the sentence. It is always a noun or pronoun. It always does the action in the sentence, otherwise known as the verb. The subject can be common or proper, singular or plural.

Example sentences:

"The young man ran the long marathon." Man is the simple subject in that sentence.

"The phone's keyboard was acting up." Keyboard is the simple subject in that sentence.

"The papers blew across the room." Papers is the simple subject in that sentence.

*Note: Simple subject is a term referring strictly to the subject. The complete subject is everything before the predicate/verb.
The predicate is the part of a sentence that states what the subject does, has, or is.

For example. In the sentence "He kicked the ball," the phrase "kicked the ball" says what he does.

In the sentence "She owns a pony," "owns a pony" says what she has.

In "That ball is red," the predicate "is red" says what the subject "ball" is.
Assuming that the questioner meant "does" instead of "dose", this is the definition of a an active verb.
You can usually think of the subject as the DOER of the main action of the sentence. "Mary ate the Apple". Mary is the subject; she is the one who DID the eating. It gets much more complex than this, but this is the basic idea.
Simple predicate.