I would encourage reading this post first if you haven’t already read the post – Cooking Fever Game – Available on Computers, Apple and Android Devices – October 7, 2020 if you decide to play Cooking Fever. I believe the first restaurant you have access to is the Fast Food Court. I recommend staying to Level 10 and below for any restaurant until you get the Casino option and have earned 70 gems from the Casino and daily playing.
Saw this on YouTube – https://www.youtube.com/watch?v=QiZX-3ywQnA
Direct link – Cooking Fever – Salad Bar Tutorial (about 2:03 minutes long) https://www.youtube.com/watch?v=QiZX-3ywQnA