I've build in the Coaster-Editor a Coaster (Typ: Looping-Coaster) but where i have to save it to use it in Sandbox?
Thanks
Sorry for my bad english, im german!

click on the coaster to bring up the menu thing in the bottom right. then click on the options until you see a small 'save' logo (it looks like a floppy disc). click on that to save your coaster.