you can use FIRST's "What's going on in my area?" tool:
http://www.usfirst.org/whatsgoingon.aspx
Nebraska doesn't seem to have
any FIRST event or team going on (as Dave said), but maybe you live close to a neighboring state? apart from south dakota all neighboring states seem to have a alot going on...
EDIT:
Nebraska has an FLL championship:
LINK
and also Jr.FLL fairs.