Zoning is not overly complicated. As long as the place you rent is zoned for retail, you can do food & beverage sales. You do need approval from the Fire Department, which takes a few months, but in practice this is often done after opening.
There is an extensive post on how to open a limited liability company somewhere on Forumosa, which walks you through the process. It's not super-complicated, but I recommend hiring an accountant for this, since you're bound to make mistakes, which will extend the whole process.
What kind of eatery are you planning to open? If you are willing to consider operating outside of Taipei, I can connect you to some real estate people in Zhubei for retail space.