I need your help in creating checkpoints in game!

Hi ! I need your help in creating checkpoints in game!
I’m creating 3D game on Android platform , game person have lives and coins which he’s collecting during levels. In the end of the level there’s a saving platform for coins and lives in game.
I’ve made a slot for a savings through game instance and loading and saving function, loading function connected in game mod , saving function to platform.
In game instance I’ve create a slot for saving checkpoints and saving functions and loadings.
Now I need to make a function for player where he can choose from who’s part of game he wants to start : he could restart level and start from the beginning or he could start from the last checkpoint, how can I make it?
When I connect checkpoint loading in game mode after loading level than after player making restart he starts since a checkpoint but not from the beginning of level