I speak around the world about UX strategy, product design and marketing. I've advised startups, launched two of my own. Advised dozens of startups & late adopter business to level up in the digital space.
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.
Having been in these straits before, I'm going to give advice that's a little different.
The key to starting a business is less about aptitude and more about ability to have a market. The only difference between you and someone who is doing what you want to do already is they have established relationships that enable them to get work consistently enough not to be "living on the bare minimum" for a while.
I think the nature of your questions means that you don't necessarily have all of these things into place yet and that you're hoping your moxie/hustle will get you through. While it might for a while, eventually you'll come to a realization if it's not working, that you need to do something else quickly for money and you won't have the capital to make that possible as much as you might right now.
My suggestion? Find work with a more established person in the field you want to be in. You need experience to answer the questions you have, even if you have some already. More importantly, you need to get the handles down of workflow and see how other people run their businesses because the market opportunities that exist while other people make mistakes is how you develop a product or service that you believe others will pay for.
As for whether to inform employers that essentially, "I'm going to take this job for now, but my dream is to do my own thing, so I might leave in an unspecified time when that happens," it'll just make someone not want to offer you the job. Maybe someone will appreciate your talent and see you for who you are and mentor you. But these scenarios are few and far between and even if they happen, without a lot of hand-holding and guidance, it just leads you to think you're closer to where you want to be than you are.
The key is getting your reps down and getting a sense of why you'd be able to establish yourself in this industry better than someone with more money, contacts and so forth.
Right now, you need money and that way, you can continue hustling your dream in the hours when you're not at work and on weekends and so forth. Not to do that forever, mind you, but for where it sounds like you are, it might make the most sense and get you a lot further along faster than hanging a shingle at this present time.
Applying for a Tax ID (EIN) is pretty simple and can be done online during the week by visiting: http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Apply-for-an-Employer-Identification-Number-%28EIN%29-Online
Doing so will enable you not to have to use your social security number when you have situations that ask specifically for a business ID, like doing business with other parties or for billing certain entities.
The bigger issues are what kind of "tour" business are you talking about? Not knowing what state you're in, there might be local or state laws regarding the kind of business you're looking to perform that you'll want to be aware of. I read this as "tour" for musicians, but if you're talking about taking people on tours around a certain area, there will be a variety of liabilities that you'll want to ensure you're protected from in the event something happens.
Hope this helps get you started.