Dear Yanteng,
Welcome to the community!
It's great to hear about loongarch. I think the best place to discuss loongarch is the main community development mailing list:
https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/
That will be the starting point, and folks there will be able to discuss what the next steps here would be to make loongarch a recognised alternative architecture for the community.
We do have a "welcome to Fedora" system in place, but given that you already have quite a bit of FOSS experience, I don't know if you need to follow that. Just getting started with a discussion on the -devel list would probably be a good enough starting point for you? Please let us know what you think will be most helpful.
https://pagure.io/fedora-join/Welcome-to-Fedora