What is the best, working in a company with routine working hours, rules and fixed salary or doing your private business regardless how much you gain?

Interesting Question..
The best is what you choose according to your personality and what you want to do in your life.
Working in a company is safe.Even with routine basis, you can build up your experience and succeed both professionally and personally (that's depends on you).
Starting a business is risk taking , no guarantees to have a successful one.I think it is interesting because it is full of challenges.You have to consider a lot of elements first(business idea, market needs,working hours, finanace .....).

we can say it's both.
Because once you will start your own business it's hard in begining but i will pay latter.
With company you work for it's pay good in begining but u will not much more in future 

I think Both, time management.

For me leaning and gaining the comptencies,proficiency and readiness of the skillset is improtant before getting into your won business.
Works makes you learn under pressure,create network and build relationshiop.
Once you become expertize and have strong readiness of the skillshet then step into the bussiness of your capilibities.
There would be no doubt that you will excel and do fantasticlly well in the business.