You need to follow the requirements and have composer installed. With this installation you can manage easily your Thelia version with composer, require new dependencies, etc.
If you want to use docker please follow this way.
Download the project
composer create-project thelia/thelia-project YourProject 2.5.0
Launch the database installation
php Thelia thelia:install
That's all, your Thelia is now installed, but depending your web server you may need to do come configuration :
Insert demo data
Now if you want a demo data with fake but realistic products execute
Create an admin account
php Thelia admin:create
Require existing modules
If you want to add a module made by our community you can browse this list and execute the
composer require command attached to it to download it.
After that you can enable and disable the module in the modules pages in your store back-office.