If I want to post a review of a cafe not currently listed, how do I do that?
Welcome to the forum Tania :)
First the restaurant needs to be listed
click on this link https://www.tripadvisor.com/UserReview-p2178
click on restaurant
enter the name of the restaurant and follow the prompts.
You will need the name, address and URL of the restaurant you wish to list.
On the Green Toolbar at top of the page, on the right hand side, click "write a review".
It will have a search pane in which you input the restaurant's name and location ( city/town).
If it cant locate the restaurant ,you will find in the text an invite to "Tell us about it" or similar words. Click on that and give as much detail as you can.
TA will then try and check out the property and, all being well, will notify you that they have listed it. Then you can make your review.