Having experience in the brewing world is a must if you are going to open/take over a brewery. As has been said it is a substantial risk and the rewards are not as high as the risks.
It is also, as dmtaylor stated, a ton of work. Brewing is a very small part. Getting the business model established, filing for a brewing license, and getting label approval for any beer you make are necessary and tedious parts of the business. The brewing portion is just a very small part of it. You have cleaning, contracting for grain and hops (which will be hard the first year or two), maintenance and repairs on the equipment, and all the bookwork is daunting.
Years ago, I talked with a professional brewer about opening a brewery. He said one word, "don't". That is why I took a part-time gig at a brewery when I retired from my career job to get a feel for what it took to operate a brewery. It cured me. I chose to continue perfecting my homebrewing skills instead of jumping into the big pond that has become very competitive. However, I do help out at breweries from time to time because I love doing it. I don't want to burst your bubble here, just making you aware that if you don't have any experience in the field, it might be difficult to successfully pull this off. I wish you the best of luck in whatever you decide to do.