Here is how I would match the character descriptions to the characters:
Lennie Small: Has trouble understanding social cues and norms, which leads to tension and problems in his interactions with others. Despite his good intentions, his inability to read social situations means he often ends up hurting people unintentionally.
George Milton: Acts as a guide and protector for Lennie. He looks out for Lennie and tries to keep him out of trouble. He understands Lennie's limitations and helps explain social situations to him. Their friendship provides mutual care and support.