13. Where do I type the commands? (by hosting type)

"The terminal" is a black window where you type one line and press Enter. How you open it depends on your host.

Your hostHow to open the terminal
CloudPanelLog in to CloudPanel → Sites → your site → Settings → SSH/FTP, and connect with the user shown there (or use the File Manager to upload files).
CloudwaysCloudways → Servers → your server → Master Credentials for the SSH details, or Launch SSH Terminal.
cPanelcPanel → Terminal (if it is missing, ask your host to enable SSH).
Baota (BT) panelBaota → Terminal on the left, or SSH.
Your own server (VPS)In PowerShell or Terminal on your computer type ssh username@server-address.
Not sure / no accessAsk your developer or your host's support, or buy the install service on the website.

Key points:

Host screens change from time to time. If a button has another name, follow your host's documentation.