Laravel problem with php artisan serves

I'm following a lesson from Laravel 5.6, and during class, I created the project in laravel, already with all the tools installed. NPM, Composer, Xampp etc.

Then I ran the command:

composer create-project --prefer-dist laravel/laravel projeto

I did the whole class procedure, and tested the project using the web server with the command:

php artisan serve

I joined the project and everything went well. Soon after, I made git push , versioning my project. This lesson has been tutored and tested at home.

The next day, I wanted to continue my class from where I left off, but from my job and not from home.

I made git clone , and tried to start the project again with the command:

php artisan serve

And he introduced me the error:

  

PHP Warning: require (C: \ Users \ mazola \ Downloads \ Udemy-Laravel-Routes / vendor / autol oad.php): failed to open stream: No such file or directory in C: \ Users \ mazola \ Do wnloads \ Udemy-Laravel-Routes \ artisan on line 18

     Warning: require (C: \ Users \ mazola \ Downloads \ Udemy-Laravel-Routes / vendor / autoload.p hp): failed to open stream: No such file or directory in C: \ Users \ mazola \ Downloa ds \ C: \ Users \ mazola \ Downloads \ Udemy-Laravel-Routes / vendor / autoload.php '(include_path =' C: \ xampp \ php \ PEAR ') in C: \ Users \ mazola \ Downloads \ Udemy-Laravel-Routes \ artisan on line 18

     

Fatal error: require (): Failed opening required 'C: \ Users \ mazola \ Downloads \ Udemy -Larvel-Routes / vendor / autoload.php' (include_path = 'C: \ xampp \ C: \ Use rs \ mazola \ Downloads \ Udemy-Laravel-Routes \ artisan on line 18

Not satisfied, I did a lot of research, and I ended up finding some "solutions"

One of them was to run the command:

composer update

I circled, and gave php artisan serve again. And I went to test in the browser accessing localhost:8000

This time I accessed, and started the server, however, when I accessed the page it presented me with an error page:

  

500 Whoops, something went wrong on our servers.

It's worth noting that after I uploaded the project in git and made the clone again, the .env file was no longer available, only .env.examples .

Then, I entered the file .env.examples and "saved as" naming it to .env , and tried to start again, and ended up going without problems, on the routes I had already configured in class, with no errors .

I do not know what procedure to do to start the project in the correct and standardized way, what procedure did I do to work out the standard used in the market?