Dear all, I`m new to Apex REST/SOAP web services world and I`m struggling with a project of integration. What I have a API documentation from client which contains cURL examples, fields and sample JSON response. My questions,
1) How should I start and how can I call this API data inside Salesforce? I need ability to pull and push the data into Salesforce.
2) Are there any changes that need to do in external API system or can I call web services directly in Salesforce if I have login ID and Password of API?
3) In integration projects like this, what should be first step? What information will I need from client to start the integration?
 
I have read few articles online on REST but none of the article provide real time examples. Can you Apex Gurus please help? Any help is much appreciated.
 

Challenge Description:

• Upload a specified zip file as a static resource. The zip will have directories with images and you have to display a specific image on a Visualforce page.The page must be named 'ShowImage'.
• This file must be uploaded as a Static Resource named 'vfimagetest'.
• The page must have a Visualforce apex:image tag that displays the 'kitten1.jpg' image from the 'cats' directory of the static resource.

Screenshot of Visualforce Page:

Screenshot of Resource Page:


Screenshot of page preview:


Exact text of error:
Challenge not yet complete... here's what's wrong: 
The page does not include a reference to the specified image

Can't figure out whats wrong, everything looks like its working perfectly and I used the examples in the module as a base for the code.