There are two kinds of accreditation: regional and national. Most non-profit (and a few for-profits in recent years) colleges and universities have regional accreditation from the regional accreditor in their particular part of the country. This body is comprised of other educators from other institutions and have a whole process for you to get regional accreditation.

Given it's so prestigious and it's hard to strip once it's conferred, the process to get it is stringent and difficult. It's also expensive.

Most startup schools like yours will often eventually apply for national accreditation which has its own standards, but is not always accepted by employers, though nationally accredited schools are able to receive Federal Student Aid in the form of grants and loans (which is why so many startup schools want it, it's a reservoir of free cash. (or seemingly so)

The issue here is the road to get here is a 5-10 year process generously and surely an endowment in the millions to get from startup to where you'd like to be. It's not impossible, but it's also not a straightforward process.

Honestly the better way to do this would be to establish your processes and if you have the capital, find a smaller college that might want to partner with your institute to offer degrees, it would give you direct access to accredited programs, except you'd obviously have to split any money it made.