https://www.senate.gov/general/contact_information/senators_cfm.cfm

Though they are even harder to get a hold of than House Reps, you can still try and at least they can’t say you didn’t.  Kinda, takes away their excuses.

Also know the Senate Committees https://www.senate.gov/committees/index.htm

See their scheduled meetings https://www.senate.gov/committees/hearings_meetings.htm