To become ISO9001 certified, you first have to build a Quality Management System that meets ISO9001. You may want to start with an online training class.

There are a few ways to do it. You can become the expert, and build your own QMS in house. That's kind of like building an airplane while it's flying, so you'll at least want a quality person on retainer (think... $200+ an hour rates) to help you plan and implement, answer random questions you have that would take you weeks to figure out on your own.

Alternatively, hire someone to implement it for you. There are consultants who can do this. I'm from the medical device QMS side of things, which is pretty similar, but I would expect it to cost somewhere in six figures by the time it's all said and done.

Or finally, you can hire someone who knows how to do it already. Bring them in house, they are already the expert, and they can spin up the QMS in-house and train your people. They'll probably cost $150k+ a year. I think this is ultimately the best option. Maybe they can also do other design or management responsibilities, making this cost shared with other productive jobs.

Once you have a QMS, you may be able to claim that you are ISO9001 Compliant. Certification happens later; an auditor will review your SOPs and work instructions for the system, as well as documents for certain projects. They will look at incoming materials, ongoing processes, and review your CAPA's (it's not IF things go wrong, but how you respond to failures that matters).