Opening a restaurant/bar involves the same issues as starting any other kind of business -- and then some.
You need to be concerned with forming a business entity. If you have investors (restaurants can be capital-intensive), you'll have to be aware of securities laws as you prepare your investor documentation.
You'll have zoning issues to make sure that you are locating your restaurant/bar in an area that's zoned for commercial use.
Don't forget certificates of occupancy so that your premises don't become overcrowded and violate fire laws.
Ah yes, then there are liquor licensing laws, health department regulations, food service certifications, employment laws that will cover your workers, garbage removal, and sales tax laws -- just to name a few.
Get the help of an attorney experienced in working with restaurants and food establishments, as there are a lot of curlicues in this line of business that most attorneys may not be familiar with.
Nina L. Kaufman, Esq. is an award-winning New York City attorney, edutainer and author. Under her Ask The Business Lawyer brand, she reaches thousands of entrepreneurs and small business owners with her legal services, professional speaking, information products, and LexAppeal weekly ezine. She also writes the Making It Legal blog.