How to add CSS to the module? I am very new to Drupal. I have an html form and I want to create a module that take the html of the form and create a table in the database and saves the form values in database.

what i have done i have created a form with form api (with buildForm method) my form is being rendered and i have converted it into Twig template (it is being shown in twig template), but first my CSS is not getting loaded.

My library file: mymodulename.libraries.yml

bootstrap:
  version: 1.x
  css:
    css/bootstrap.min.css: {}
  js:
    js/bootstrap.min.js: {}
  dependencies:
    - core/jquery
    - core/drupal.ajax
    - core/drupal
    - core/drupalSettings
    - core/jquery.once

global-components:
  Version: 1.x
  css:
    css/baselayout.css: {}
    css/form.css: {}
    css/wisdom.css: {}

  js:  
    js/jquery.smartmenus.min.js: {}
    js/custom.js: {}
  dependencies:
    - core/jquery
    - core/drupal.ajax
    - core/drupal
    - core/drupalSettings
    - core/jquery.once
CSS lives one level further down in a libraries file; under system, module or theme. e.g.:

bootstrap:
  version: 1.x
  css:
    theme:
      css/bootstrap.min.css: {}
  js:
    js/bootstrap.min.js: {}
  dependencies:
    - core/jquery
    - core/drupal.ajax
    - core/drupal
    - core/drupalSettings
    - core/jquery.once