Page title and body field of specific page
If you must do this in twig only, you can use the drupal_field() function provided by the Twig Tweak module.
For example, to print the title of node 2:
{{ drupal_field('title', 'node', 2) }}

Or to print the body field for node 2 using the field's configuration from the teaser view mode:
{{ drupal_field('body', 'node', 2, 'teaser') }}

Or to print an image field with custom formatter settings:
{{ drupal_field('field_image', 'node', 2, {type: 'image_url', settings: {image_style: 'large'}}) }}

I'd probably aim to create a custom view mode here and then print the whole view mode as one chunk with the drupal_entity() function. For example:
{{ drupal_entity('node', 2, 'my_custom_view_mode') }}