Hi, personally, I would advise copyrighting your designs/scripts(well if you are a writer like I am) and story pages before showcasing anything, anywhere. Certain ideas, names, titles, cannot be protected but if someone blatantly rips off your comic/characters/story and you have it all copyrighted you'll have a lot better chance fighting in court than you would without it, even though technically the moment you create something it is already your property.
http://www.copyright.gov/
^if you have time enough, try to understand the basics of copyright law and if you have the $ for the fees(it isn't expensive) you can copyright your comics yourself without legal help. Turnaround time is usually a few months, but once you submit your work your copyright on it goes into effect the same date that it is accepted for processing, and you'll get a certificate in the mail in a few months. For my series(which I am going to begin posting some of it on here this month) R:ILPERSONA, I created a massive story bible with all of my concept artwork, designs, original scripts/comic pages, everything and it was all copyrighted in one shot, and then every few months when I make new material I copyright it as well.
A lot of creators pour their soul into their creation and it would be unwise to not at least have some protections on it....better safe than sorry you know? Plagiarism is to me one of the ugliest forms of theft.
Cheers,
-Starlightcitypro
www.ilpersona.com