https://jmeter.apache.org/usermanual/get-started.html

1.0 Overview When using JMeter you will usually follow this process:

1.0.1 Test plan building

To do that, you will run JMeter in GUI Mode.
Then you can either choose to record the application from a browser, or native application. You can use for that the menu File → Templates... → Recording

Note you can also manually build your plan. Ensure you read this documentation to understand major concepts.

You will also debug it using one of these options:
  • Run → Start no pauses
  • Run → Start
  • Validate on Thread Group

and View Results Tree renderers or Testers (CSS/JQUERY, JSON, Regexp, XPath).
Ensure you follow best-practices when building your Test Plan. 

JMeter -- Getting Started_css