What is required from me is making API requests from an already made website using Wix I don't know if Wix has this feature same as easily making the website don't know where to look or where to start any help ?
Your question is not clear.
If you are looking to make an API call from a mobile app to a Wix Website then you need to use Corvid's HTTP functions (https://www.wix.com/corvid/reference/wix-http-functions.html)
If you are looking to make an API call from a Wix site then you need to use Fetch (https://www.wix.com/corvid/reference/wix-fetch.html)
Read the difference between http-functions and wix-fetch here: wix-fetch vs wix-http-functions