Hi,
I manage many Linux (mostly Ubuntu) servers on or off-premises for more than 15 years. Not only for web hosting, I also manage database and file hosting servers.
**Server Setup and Configuration**
For web server, I can setup both Apache and Nginx and some extensions or modules as needed such as PHP. Just tell me how would you like to build you web app, or you can tell me just what modules or extensions you need.
I can also setup a database server for you if needed, such as MySQL or PostgreSQL. And I will optimize the web server and database used to improve your website performance.
**User Management and Permissions**
Yes, I can setup users and/or groups and assigning them appropriate permissions to ensuring that only authorized users can access certain files and directories.
**Security and Firewall Management**
Yes, I can setup ufw (Uncomplicated Firewall) and fail2ban for you. And I can also setup SSL certificate if you have one for your domain, otherwise, I can setup free SSL certificate from Let's Encrypt, so, your website can securely accessed worldwide.