In the short term? Direct action and protests. Some have managed to shut down an israeli arms factory or two, or have forced divestment.

Long term is organizing via socialist orgs as always (FRSO, PSL, etc). The specifics on what you do depend on the orgs.

In addition to what Aquilae said, agitate and educate, don't tolerate comfortable ignorance from those around you. You don't have to be one of those "umm acktually" type of people, but just make sure you're combating misinformation from friends and family, encourage people to actually care about things, instead of just "checking out" and living in a comfortable bubble.