You're in Love, Charlie Brown (1967)

With the school year coming to a close, Charlie Brown is trying to work up the courage to meet his dream girl, whom he only knows as "The Little Red Haired Girl." However, he's too nervous to go meet her upfront and all his attempts to impress her at school backfire disastrously. His friends, Linus and Peppermint Patty, try to help, but only aggravate the situation, while Charlie Brown desperately tries to find a solution to this romantic conundrum.

Unfortunately the movie You're in Love, Charlie Brown is not yet available on HBO Max.