How short are we talking? If you've never made any comics before, I recommend doing a few 1-page comics or maybe some 8-page or fewer comics to build your skills. Doing a 1-shot (a single 24-page story) is just fine, too. The point of advising new comic creators to do short comics is so that they develop their skills and learn how to complete projects, while not locking yourself in to beginner mistakes you'll likely make, especially in character and setting design. Short comics can also get you usable feedback more quickly, so it supercharges your skills and confidence.
If you do a complete story and then decide you want to do a continuation later, then you can! We just don't want you to start your 1000-chapter epic series before you have the skills and discipline to pull it off!
Finally, short-form content is great for Bluesky, Reddit, or most places online. Suitable places to post longform comics are much more rare. You can also post them here, although if they are true one-offs, you probably won't get the level of audience response you'd like to receive.
