Custom Permalinks for Posts

I would like to customize my permalinks for my posts. I would prefer to use the post name however some are too long, so I don’t want to just apply a custom structure. By doing a google search, I’ve read about post slugs but don’t see how to do that. When I edit my pages, there is a button that says ‘Edit’ and I can change the individual link. However, for posts, I only see the ‘Change Permalinks’ button. Is there an easy way to customize every post’s link?