Drupal 8.x

I've got this userflow, but commerce webform order doesn't do what I want - I want to submit the webform after checkout. 

What I've got figured out and is working:

1) User A fills in webform A and submits it

2) Car dealer B receives an email with a link on it to a different webform  B

3) Car dealer B fills in said webform B to reply to User A

4) Car dealer B then has to pay X and go through a standard checkout to submit webform B

I recently had to set up a multi-site instance of Drupal from scratch; and now, I have to do so again. I recall it being fairly painful, due to somewhat scattered and/or out-of-date documentation. Therefore I have decided to document my procedures in excruciating detail, for my own future use and (hopefully) to help out others.

I was a user of Drupal around 10 years ago, so I do have basic knowledge.

I have just tried to install Drupal 8 and I cannot get it to work. I am trying to install it manually.

I upload the Drupal 8 zip file to my server. I unzip it. I go to the web address and get a 500 Internal Server error.

From my previous knowledge, I create a database and user. I go to Site\Default\default.setting.php and try to put the database details in there and still nothing. How do I get around this?

Can anyone help based on Form Value, how to disable sending an email that has already been configured within admin/config/workflow/workflows/manage/case_workflow/transition/publishing_review_to_publish . I am using workflow moderation.

Drupal 8x 

I am using workflow moderation to send emails within publishing workflow at various states (draft , publish etc). 

New requirements:-

Introduce 3 new fields,

                    1. "Send Email"(checkbox) within the content type .

                     2. "Email Content"

                    3.  "Email to"

Hello

 We are validating a SSL for our Drupal 8 site and we need to upload a file inside a folder like this:

 webroot/.well-known/validation/file.txt

 But when we try to access we get: 

Not Found

The requested URL was not found on this server.

How can we do to allow the browser access to this file? please note the dot on first folder, we have already uploaded .

Any help?