One day one shots

My group just finished up LMoP and are getting ready to play WDDH. I’m having them make all new characters that will follow them through future campaigns. I want to have the first session of the new campaign to be a one session one shot adventure where they can test okay their new characters and for the characters to meet and have a back story to how they all ended up in Waterdeep. We play on FoundryVTT what are some of your favorite one shots that can be played in a single session?