Before you can start pushing back against Trump, you need to know who represents you in Congress.
Find out who your Congressional representatives are by plugging your zip code and your state into this web site:
This web site is better for learning who stands for you in the House of Representatives (plug in your zip code and it will narrow the choices to two. The name that seems more familiar to you is probably your House rep):
Once you have pinned down your two Senators and your House Rep, pull up their web pages. Scroll to the bottom. If their offices aren’t listed there, go to the Contact page and find them.
Pick the state office that is closest to you (NOT the Washington DC one).
Find the phone number for that office.
Put it in your phone.
Repeat for your other two representatives.