Installing Drupal

hey all, 

I have to install, with composer, the Multi Site with D8 locally on XAMPP.
I have read various articles but I have difficulties when I install the first site I get the error page not found
In the various examples seen, someone installs it on the main folder, while others do it only in the two folders created in sites.

Given the amount of advice and material, I find myself in difficulty. A help?

Hi.

We moved the site today to the client server. The automatically created "htaccess" file, which sits in the "/web/sites/default/files" folder, does prevent the apache (php) from creating files (image styles).

The SetHandler statement in particular:

When commenting out the line all works as expected. The files are written and the apache can deliver them via request (browser).

Folder rights and owners are correct.

I guess it must be some kind of server setting. 

I am trying to install Drupal 8 on Windows2012R2 using composer. I have an admin account.  

I am getting the following errors. Any guidance would be greatly appreciated!

Installed Drupal8 on the LAMP web server of the Ubuntu 18.04.3 LTS operating system.
But when in the toolbar I click on the Content, Structure, Appearance tabs and all the others, I have an error:

404 Not Found

The requested URL was not found on this server.
Apache/2.4.29 (Ubuntu) Server at localhost Port 80

How to fix the error?

With D7 support coming to an end I will need to change my 2 websites.

I've been runnig drupal since 2006, doing the work myself at an elementary level, developing in a hosted environment, using ftp.

This was work that may have taken more time then a pro would need, but it was doable.

Now I am trying my hand at D8+ commerce, which needs (?) composer.

It seems like every step I manage to take throws me another curve ball.

I did manage to install composer and a local development environment, and even had it running (I use ubuntu 19.10).