So I've been running a homebrew campaign based off of Harry Potter for my friends. The thing is, I'm still getting the hang of DMing, and I'd be interested in running a pre-made campaign. This way I can see the type of thinking to base my own off of. The thing is, I think most of my players are more interested in the Harry Potter universe that I've created as opposed to typical fantasy universe. We don't get a lot of time to talk as a group (we use a discord server for our sessions), but I want to present the idea to them when we can talk on a chat, so we can have a discussion about it.

Along with this, do y'all have recommendations for a pre-made adventure (on the shorter side, although not a one-shot) that we could use?

Depends on what they're into. The Harry Potter has a great theme so its fun and easy to connect with, so I recommend finding another theme. For example, see if they would like to try Gothic horror then Curse of Strahd would be a great fit. Here are some other examples:

Pirates! The Ghosts of Saltmarsh 

Dinosaurs and zombies: Tomb of Annihilation 

Heavy Metal Fantasy: Decent into Avernus 

High fantasy: Storm Kings Thunder 

Western: Lost Mine of Phandelver

See anything you like?