Theme development

In my local test server I have created a Drupal v. 7.41 and I have installed Adaptive Theme (AT Subtheme 7.x-3.2) and Clean Corporate Theme 7.x-1.2, which I have set it as the default theme.
My main horizontal menu is responsive when I change the screen width (becomes vertical when screen width gets narrower), but the menu toggle button is not displayed, as in the demo site (http://live-corporate-profile.pantheon.io).

In drupal 7 you could use "views_get_view('view-name', 'view-display-name') to render a view in the theme template.

Does anyone know the way in drupal 8 to render a view in the twig template?

(My case is very simple, 2 column user profile, right column is a view of viewed user content)

I'm using a custom theme and when I integrated my own html.html.twig structure (based off the one from core), the admin toolbar disappeared and hovering over block/view elements no longer shows the configure/edit menu actions. The top toolbar is there when I access one of the admin pages on the back end, but when viewing the site itself, it's not there... even though I'm still logged in as admin. I've cleared the cache multiple times, but still no dice.

Do I need to render/output the display of the admin toolbar in my htm.html.twig file?

I tried:

{{ date|date("m/d/Y") }}
Throws:
Exception: DateTime::__construct(): Failed to parse time string (<span data-quickedit-field-id="node/1/created/en/full">Thu, 02/11/2016 - 22:11</span> ) at position 0 (<): Unexpected character in DateTime->__construct() (line 515 of XXX\vendor\twig\twig\lib\Twig\Extension\Core.php).

I am creating a custom .tpl file for a type of content.

I created a file field, "field_file" and want to add in the .tpl something like this:

<a href="field_file path"> Download file</a.>

I try render the contet :

<a  href="<?php print render($content['field_brochure']); ?>"> Download file</a.>

Please: how I create a link with the file path ?

hi all.my name is omar bd a wordpress themes developer and designer . in the last week i created a wordpress free theme and today a was going to convert it to Drupal . but i donot knw anything about Drupal Theme development . soo i just want to know some points :