Neither ACM nor SIGCSE has any guidelines or template recommendations for the ACM Student Research Competition (SRC) posters. Participants are encouraged to be creative and innovative with their posters and presentation.
There are many ways to create a poster, and we encourage SRC participants to explore other resources online.
Research Poster 101: LINK
Creating Effective Posters [UC Davis]: LINK
Better Research Poster: this video gives the context in which the poster sessions are organized and how one might approach the design of the poster:
https://www.youtube.com/watch?v=SYk29tnxASs
Butter Poster Design Templates: https://derekcrowe.net/butterposter
Additional Template Video: https://www.youtube.com/watch?v=fe3ndUFw6go