How to make a saving gui after rejoin? Datastore for Guis?

For examle, im got an frame with teleports on multiple stages what you completed. Once you will complete a stage - you will unlock teleport to it. But player leaves. And when he coming back, he haves all teleports locked and he need to complete the stages again. I need that frame to stay for the player who completed some stages to make players stay in game.

Other expample for update im working on, im wanna make shop with items and other features. So i have made gui what changing the speed of player. Im wanna make buttons what unlocking it for some points. I know how to make it ready to be bought, but im wanna know how to make it stay bought after player rejoins.

I know how to make datastore for points, but how to male guis save? Also if you can say what to do to save gears?