Forget about it. Nothing is Nepalese here, everything is jaat vaat community and society- Newar Community, Tamang society, Bahun Dhukuti Khelne Society, Sherpa ko afnai nanathari society. Nobody cares about Nepal as a whole and educated Nepali youths don’t give a shit about all these communities only buda paka and chauri pareka do. So forget about any Nepalese societies in US, you will find none.

Here is the link for
NASEA https://naseaonline.org/local-chapters-of-nasea/nasea-region-organizations/
and ANMA http://www.anmausa.org/Home/Organizations

You can find the contacts of the local chapter under each organization.