There are some programs out there that let you make your own game. But my memories of making my own board game are a bit childish and very old school. They date to fourth grade, when I made a game from a poster board, that used dice, that was inspired by getting simple arithmetic problems correct to move forward and win.
Recently, my reading about game design has been similarly old school, inspired by Candy Land. Candy Land was a game designed for children on a polio ward, invented by a retired school teacher who also had polio and was confined in the same ward with the children (because polio required a quarantine, and was a disease that was much more common among children vs adults).