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.