Carly = Cory, Sam = Shawn, Freddie = Topanga, and Spencer = Eric.

Although on the other hand (https://www.reddit.com/r/boymeetsworld/comments/173xtn4/comment/k47q90j/?utm_source=reddit&utm_medium=web2x&context=3), Carly wasn't an average student who at times was a slacker and Freddie was basically a less socially awkward Minkus. He only became Topanga especially in the sequel series.