I saw the thread with an breh who got his MBA and his job prospects jumped almost instantly. My undergrad is in journalism

and his was in business.
I got about 15 months left on active duty military. Was thinking about using tuition assistance to get my MBA right quick.
Is it even worth that much on the outside. Ultimately I’m looking towards the entrepreneur route, but still need to get a day job while I’m growing this side business
Gonna be a long post but here's what I've gathered from my father, colleagues and mentors that have gotten their MBAs and Master's. Schools range from Harvard Business, Stanford, Yale, Booth to UMD and Johns Hopkins.
Why get an MBA?
The million dollar question. Why get an MBA and is it worth it? The answer to that question lies in what you're looking to accomplish in life and if an MBA would be a tool in accomplishing said goal. The biggest reasons as to why one should be inclined to get an MBA is if:
1. They want a bump in their career prospects, particularly in Corporate America
2. They want to pivot industries or get into specific industries
3. They want to tap into a strong alumni network
4. They want to "check the box" as it concerns to their corporate profile
Getting a top 20 MBA definitely opens the door for career prospects to the individual who completed their MBA. Whether it be consulting, banking, tech ops etc, a lot of top companies recruit out of top MBA programs. For industries like banking, top level consulting and top finance, if you don't get recruited out of college, then it's only through an MBA you can generally break in (not a hard and fast rule but generally.) Alumni networks goes without saying. Finally, "checking the box" is something that is becoming more and more the norm as the financial premium of an MBA becomes less attractive as before. Say for example you're 26 and make 120k, the avg. starting salary of a top 20 MBA is roughly $125k IIRC. The $5k bonus isn't really good ROI if you have to go almost $250k in the hole to get it. This is where part-time MBAs have become a lot more popular for people who just want to "get the MBA" and be done with it. It's almost like the bachelor's degree within some industries.
For you OP do I think it'd be worth it? I'd say it depends. If you can go to a relatively good school for free and the opportunity cost is low, then by all means. What you learn while in an MBA will usually give you general knowledge as to how most corporations are run and the strategy behind it. You'll usually take some general courses in accounting, economics, business strategy etc. It's good knowledge that can really be applied anywhere.
As per your ambitions to become an entrepreneur. Getting an MBA does not necessarily equate to being a successful business owner nor does getting one hurt. There are successful entrepreneurs with an MBA and many without. An MBA can give you access to capital to start your own business, or you can get it out the mud like others. My father got his MBA and worked in Energy trading for 15 post-MBA and recently set up his own Energy transaction firm. When he talks to his clients I'm sure him getting a top-MBA helps solidify his case. But I do also think his 15 year track record also speaks for itself.
One thing you may want to consider is a part-time program. If you're older than they typical full-time candidate (25-28 yrs) then a part-time program might be worth it as you can still earn while you learn. The programs are offered as either evening or weekend programs and usually cost way less than the full-time program. This is particularly useful for people who want to "check the box" as it concerns the MBA.
Finally, the MBA is more general than a Masters. A master's is better if you have a firm idea of the type of work that you want to do and the industry you plan of building a career in. An MBA is better for mid-career pivots. For example, the VP of Brand Marketing in my company got her UG degree in English and History or so. She worked for like 3 years in books publishing before saying that wasn't for her. Got her MBA in Marketing from Kellogg and since built a career in marketing at very notable companies since then.
OP, if you're young, have the financial resources, have the "tablestakes" and are single, then I'd say go, full-time if you can.