It is so developmentally typical. She is vocalizing and enjoys hearing her voice. She thinks she is talking; but unfortunately she only knows that one word "screech". lol
It is also exciting for her to see the response she gets out of it.
She needs to be appropriately directed so she understands that vocalizing is not the problem, it's the level of sound that is the problem.
Often the more attention you pay to it, the more a child will do it. But, there are times when you cannot ignore it (such as in public...not fair to others.)
When my daughter screeched, I put my hand gently on her mouth, made eye-contact, and told her "Quiet voice", and made a quiet sound which she then tried to copy. :) I also used distraction (redirection) to a new activity when she did it.
Pay careful attention to what is going on when she screeches. After calming her, use the appropriate labels/words/phrases for what it is she seems to want,(e.g. food, to be picked up, a toy) and work with her to learn how to say it. She may seem young, but her language will develop quickly.
Some people also use sign/hand language. This can be a great method because it is subtle, and there is physical activity involved which creates deeper neurological connections, and increases overall brain development (including language).