New to USA - Masters vs. Staying with my mentor I'm 23, I recently immigrated to USA (legally lol) and I'm loving the amount of opportunity here and I sure want to make good use of it. However, I'm confused about a major decision and need your opinions.

I graduated from India with a Bachelors in Engineering degree (Computer Science) from an okay-ish standard University. Lots of people I run into tell me that I should get into a Master's program, as it will not only give me a great education and name of a USA school on my resume but also teach me a lot about culture and life in general.

But on the other hand, I have my uncle who is a CEO and founder of a multinational and multi-million software development company, which is where I'm working right now. Since I live with him too, we talk a lot and he is my mentor. Despite his insanely busy schedule, he is always willing to talk to me and answer my questions and teach me stuff. Its good for me since my life goal is to start a software company myself in future and learning from him can be a game changer. Its bad for me because I'm kinda immature, and staying with him keeps me on a safe side (CEO's nephew).

My question is, what would you do if you were me? Sticking with mentor vs. getting a master's degree.
Depends on what you expect to get from a master's degree. 

From the sounds of it, your career path certainly isn't going to be dependent on the credentials, but could perhaps be aided by a degree. 

Personally, I could see you getting benefit out of a good Masters on a couple of counts: 


An introduction to where the state of the art lies. Since it sounds like you have an entrepreneurial bent, finding this state of the art could help point you in the direction of problems which have been solved, but not productized... could be a great start for a company. 
Another mentor. Having multiple people to bounce ideas off of is a valuable thing, especially when they have substantially different backgrounds. 
A chance to exercise your grit, away from the perhaps comfortable situation you're in now. A masters will force you outside your comfort zone.
The benefits you list are going to be there for sure; an immersion into American culture and life.


Of course, getting all of this doesn't require a Masters degree. You're already living in the USA, and you can try to stretch your research legs on your own.