How to load jquery in twig file
I think your question is that you want to put inline javascript in twig templates, but it does not work, because jquery is not loaded yet?

You can override the default that the libraries are loaded in the footer and put jquery and any of your own js in the header:

mytheme.libraries.yml:

mylibrary:
  version: 1.x
  header: true
  js:
    js/myjavascript.js: {}
  dependencies:
    - core/jquery


mytheme.info.yml:

libraries:
  - mytheme/mylibrary


The important part is header: true. 

If you make a dependency on core/jquery for the header, jquery is not loaded a second time in the footer, even if there are multiple dependencies for core/jquery by other libraries.

Now you can put your jquery dependend js code in the header (in this example in myjavascript.js) or put inline js in twig templates.