The most typical way to get started is to use personal connections you have: someone's cousin's brother-in-law is VP at some company, they put in a good word for you, that kind of thing. Or, leverage some connection you have to the previous companies you've worked in, or to former coworkers who've left to go somewhere else, and are in a position to hire contractors.

You can also respond to job listings looking for contractors, and tell the recruiter that you've got a team that could work together. Sometimes that works.

I did agency consulting for 13 years, it is a constant hustle but can be a lot of fun.

Remember to always be looking for the next contract while working on the last one: make friends at the company, connect on LinkedIn. Don't be afraid to sell yourself, in fact nobody else is going to do it for you. You need an extravert on staff, or an introvert who can fake it (that can be even better).

Unsolicited advice: specialize at all costs. The more you can say things like (just an example here) "we are the experts at building typescript applications for SMB retail SaaS companies", the more likely you are to get hired, compared to the company who says "yeah we'll do anything for money". You want the person in charge to be able to look at your track record and say "these guys are a safe bet, because they've done this exact thing before."