It is likely that your J1 sponsor will keep you very busy, and you won’t have time for much else. You need to find out from that sponsor just exactly what you can and can’t do with that J1. At the community college where I teach, you would be barred from any of the programs supported by federal grant money, and you would be charged out-of-state rates for continuing education courses. I don’t know what would happen if you tried to enroll in a credit division course in non-degree status.
Since you are interested in creative writing, you might be able to find other community organizations that have writing classes or groups you could participate in that don’t award academic credits. Here is one group near where I live. https://www.writer.org/