Does anyone know the scripts for making checkpoints or something? I'm trying to build an obby myself

no

Ask Shops.

oof

You can add 1 to their score every time they finish a level and if they die you can just teleport them to the checkpoint (brick) named their score.

let lava = Game.findBrickByName("lava") // this will "kill" them when they touch it

lava.touching((plr) => {
let checkpoint = Game.findBrickByName(plr.score);
if (checkpoint) {
plr.position = checkpoint.position
}
})

something like this