Stuck on how to do an opening for a story?

That's because you don't need to start at the start. Write the scenes most vivid in your mind first. Then you might get inspired along the way for a great beginning. Write it down, but don't get hung up on it - you can always change it later. Or write out possible starting and select your favourite one. Nothing you write down will be set in stone. Nothing you write down first would be overly great, since the first draft rarely is.