What a cool project! I love
vintage league leader cards.
I'm (slowly) working on a run of league leader cards, in PSA slabs, from their first appearance 1961 through the end of the "vintage" run in 1984.
Many of the 1960's cards are getting a bit pricy, but the 1970's ones are still (mostly) reasonable. Same for the 1980's.
In terms of modern, I don't believe 2024 Topps and Topps Chrome don't have leader cards. 2024 Topps Heritage has both League Leader cards AND historical MVP cards, so that may be a good option.
Learning the history of the game and the great players is a great way to get your bearings with the sport and cards.