Learn Cache online

In my opinion, the best thing is the built-in documentation, where there are Articles, Guides and Tutorials (see "Document Type" at left)

E.g.: Caché Tutorial Topics Map

Many examples for different technologies/languages can be found in folder install-dir\dev

In a standard Windows installation of Caché, install-dir is C:\InterSystems\Cache.

@A.R.N. H Hafeel  - are you specifically interested in Caché or are you looking for the latest and greatest and therefore interested in learning InterSystems IRIS?

@A.R.N. H Hafeel , Following @Ben Spead 's question and assuming you want the latest and greatest w/ InterSystems IRIS (where you'll learn quite a bit that relates to Cache, but learn all the awesome new features of InterSystems IRIS too!), here's what I recommend:

Get an introduction

• Video: What is InterSystems IRIS? 

Note: You can also learn about all InterSystems products and how they compare, or learn about developing for healthcare applications with InterSystems IRIS for Health.
 

Learn the tools

• Video: Management Portal Overview (2m)
• Video: Run InterSystems IRIS Community Edition Using Docker (3m)
• Video: Install and Use ObjectScript Extensions for VS Code (3m)
• Video: Using the InterSystems Terminal (3m)

Develop an Application

• Path: Building a Server-Side Application (5h)
• Path: Building Business Integrations with InterSystems (6h)
• Course: Using JSON in InterSystems IRIS (45m)
• Course: Setting Up RESTful Services (90m)
• Path: Developing in ObjectScript with Visual Studio Code (1h 45m)

Optionally... expand your expertise!

• Choose Your Path: Connecting to InterSystems Products with External Languages (includes Java, Python, .NET, and Node.js)
• Get certified! InterSystems IRIS Core Solutions Developer Specialist Certification
• Path: Building Applications with InterSystems IRIS and Angular

Also, I'll mention that if you'd like a learning instance to play with, you can try out Learning Labs. Many courses include their own labs with starter files so you can focus on the task at hand (which I highly recommend using those labs when it's included).

​​​​​​​I hope that helps!