Please don’t ask for full scripts here… this is a place where you already have a script that’s broken and need help fixing it OR need a push in the right direction on where to start with a script.
If you want to get someone to do it for you, just use #collaboration
As for your skip button, there are already lots and lots of resources out there on how to do it.
So for your obby, I assume you have spawn points for each section, correct? If so, just create a list in the script with every SpawnLocation in order of the stages. Then you can just keep track of which spawn the player was at last, and then teleport them to the next one to skip.