Say vs Tell

You say something.
You tell someone something.

This one is incorrect

• She said me that she loved me(WRONG)

• She told me that she loved me (Correct)

• He said he had not been driving fast when accident happened.(Correct)

• He told police he had not been driving fast when accident happened.(Correct)

Now look at some common uses.

• Tell(someone) a story(Not say a story)
• Tell(Someone) the time
• Tell(Someone) a lie