wow
First off, I'm a CPA/PFS, IAR, RIA, RR, MBA. Secondly, I started out life as a steel worker straight out of high school in 1973. I've worked in accounting firms, corporations [ended up being the Controller for a fortune 500 company], taught college full time for 5 years and have owned my own business for the last 15 years.
I cannot disagree with anything in any previous posts.
1] starting a business is much harder work than working for someone else.
2] getting a business to become profitable takes years.
~ therefore be able to live on your wife's income
3] starting a business takes a 'special kind of person'. You have to be able to work yourself, manage others and fulfill or outsource all the accounting and regulatory functions.
4] you'll never make it unless you LOVE whatever your business is/does because you'll hate all the BS that it takes to keep it going.
~ therefore find an area you love and learn it. Work for someone else in
that area and perhaps, look into buying it from them.
5] you can only afford to borrowing money if you don't need to borrow.
I don't say this to be rude but, you don't even know what you don't know yet.
It is good that you are ambitious and willing to roll up your sleeves, spend a few years finding what you want to do, then do it for a few years [saving as much $$$ as you can] before setting off.
I own a CPA firm and a Registered Investment Advisory firm.
Today, if I were 20 and thinking along the same lines as you are, I'd become a machinist, get my journeyman certificate and open up my own shop. It'd take you 5 years [minimum] to get to that point. During your apprenticeship, save up $100,000-150,000 and be networking, developing future customers.
Best Wishes,