Understanding Webmin Server

In past i worked in windows server 2008, 2016, Plesk & C-Panel. I recently took help from freelancer to install Webmin/Virtualmin Local server with “lets encrypt”, FTP, Bulk mail etc and to do security settings eg, ports, firewall …. Limited attempts 2 login etc. for security. He did the task very well and uploaded website, so no doubts. Webmin is installed & is working. But I was not explained how I could manage some regular task myself. I am not sure if there is some minor task pending. 1 of the task is to configure remote desktop connection (not putty) so that I can see & connect through window OS (just like RDP). I need some1 to help me understand how 2 upload WordPress website with CMS, make email account, Delete some websites, maintain bulkmail, firewall, delete cache, SSH, SSL/Encryption, Back up regularly & reinstall backup, IP change, subdomain, name server, Link gmail api with email, how to do DHCP & DNS setting, Password of WP & DB change, Make user accounts, . Also to install magento 2.0 CMS. I need some1 to explain these & other necessary features of webmin to complete work.