There are many ways, it's easier to apply in bitcoin what you know or what you love to do.

There are many projects that do not have enough funds to finance themselves and volunteering is a good way to advance bitcoin, simply offering your human resources for what they need, not everything is programming, even developers need help.

Go to bitcoin jobs, stacker news. You can do many things from telling the person who serves you at the coffee shop if they accept bitcoin, to volunteering in a project, whether as a designer, translator, organizer, handing out flyers, bring together your local community, meetups, education, conference, there are very easy to use tools to get a business to start accepting bitcoin, there is one bitcoin PoS that gives you commission for onboarding merchants. Anything is valid, just try to see how you can contribute.

Spread the word among friends and family, help them in their bitcoin journey, it is easier to talk to people about the current problems and difficulties that we are all having in these times, they will agree with you and that is where you introduce bitcoin. bitcoin is the solution, and the solution goes always at the end. You can’t give out the answer without the question first.