The one (starting a small 1-2 person company and growing as money comes in) has nothing to do with the other (using a DevOps philosophy).
Even a 1-man business can be DevOps based. You can start implementing your Great Idea (tm) with a functioning fully containerized CI/CD pipeline, in fact there is no better time than at the beginning, when there is no cruft to take care of, yet, and before you hit a significant number of users. It's not going to take months of work; you can hack together a basic Jenkins/Docker pipeline in a few hours (if you know a lot already) or maybe days (but then the days will have been productively spent learning that stuff as you go).
Starting out with the CD part in a greenfield project is much easier than adding CD to an existing application which used manual deploys before.
You can start out with full test coverage at the start (there is no better time, for obvious reasons), including tools that verifies test coverage as part of the CI/CD.
You can easily start out with some small security measures, like checking your test suite for superfluous open ports or whatever.
You can, and should start out with cattle-not-pet right away (meaning IaC, IaaS, PaaS and all that good stuff, hosted on one of the pretty streamlined "big three" providers). Start small, scale a needed.
When you add more personel, they will start out right in that fruitful athmosphere, and hopefully many of their cheaper errors will immediately be caught by the CI/CD.