Short version: Sway/i3 doesn’t merely allow you to control your WM via hotkeys, it requires you to. Unless you know/have configured the hotkeys for opening a terminal or an application launcher, you won’t be able to do anything. As such, you are looking for a guide on how to configure Sway, rather than on how to use it. Once you know how to configure Sway, actually using it should be immediately obvious.
Sway is basically i3 but for Wayland, so guides for i3 may be somewhat helpful for you.
The man page is probably also worth a read: https://man.archlinux.org/man/sway.5
Short version: Sway/i3 doesn’t merely allow you to control your WM via hotkeys, it requires you to. Unless you know/have configured the hotkeys for opening a terminal or an application launcher, you won’t be able to do anything. As such, you are looking for a guide on how to configure Sway, rather than on how to use it. Once you know how to configure Sway, actually using it should be immediately obvious.