Thank you for wanting to open a coffee shop! I can't answer your question, but, just wanted to say thank you! I think initially marketing is important - picking the right site and pitching your business to the right people in the right way. As an older person (senior?), I envision a diner when you say "coffee shop," but I think you are thinking more along the upscale line of "coffee" shops? You will need to be able to develop a "business plan" to secure financing.
Learn all you can from your job. There are so many aspects to ownership/management. Selecting the right managers and employees, keeping them around, regulatory compliance, profits, the "customer experience", product selection, negotiating contracts/sales prices, etc. And, once you have a successful business, dealing with the inevitable competitor trying to squeeze in on your market .
I don't know that you necessarily need a degree. I would recommend researching what is available to you from the city, colleges, chamber of commerce, etc. Search for "small business owner" information, "minority business," etc. I know a college locally that has their marketing dept undertake projects for aspiring business owners. Also look into MOOCs - there are a LOT of free on-line classes!!!! If you are going to be the owner, you don't need the credential - just the knowledge!
Good luck to you!