Most DISigners do that type of thing but first we need more info.....colors, names, dates, characters, style...anything that would be appropriate for you.
But remember, we do not do shirts. We create images that you need to use for creation of the shirts yourself, generally with iron-on transfers.
The How To, Meet the DISigners and Creative Boards Welcome sticky threads at the top of the forum provide useful information for making requests and creating your projects.