Hi Wasim:
OK you need to get familiar with how to access page elements and write code in Wix.
If you take a look at these pages this will get you started.
In the document pointed to by the second link you will see how you need to wait for the important elements of your page to be ready for you to work with them using the onReady Function for the page - $w.onReady() and the TypeOfService data set that you are depending on for displaying content $w(‘#’).onReady(). It also shows how to import Wix helper apis that are documented here: Velo API Reference - Wix.com
Then you need to possibly use a few console.log() Statements to display key data that you are dependent upon that you can use for debugging purposes. When you select preview the console at the bottom of the page will display the output from these console.log calls so you can see the data your code is seeing.
While looking at the links I have provided above, you will likely see other documents that might also expand your understanding and example code.
Hope this helps