Get nodes of specified content type with REST I want to retrieve all nodes of specified content type (as example'news') with GET method with REST,
How can I achieve it?
(first I want try it with firefox RESTClient and if it work implement it in my application)
The only way that core offers is building a view with a REST display. That is, in fact, the only way in core to have collections (a list of resources) for rest.

See https://www.drupal.org/project/graphql for another approach, that allows to execute a sort of query through services.