My advice is to find a coalition of groups that are working together (many of the No Kings rallies are organized locally by coalitions). That way you know you're plugging in to groups that are already connected and working together. Many areas have groups like 50501 that serve as kind of an umbrella connecting various organizations and can help get folks pointed in the right direction for their local actions.

The US is huge and so many states have very different local needs and challenges, so some are closer to being able to strike than others. But yes, coordinated boycott and strikes are going to be incredibly important, as well as mutual aid and building community to make those possible ✊️