There is a very convenient feature in Windows that underlines keyboard shortcuts such as in the image below. If I want to select Action, I can just press Alt+a; Refresh Alt+f; and so forth. The underlines appear in Microsoft apps, installers so I can just press alt+n for next instead of using my cursor, etc. It is really wonderful and I miss it. Is it possible to get something like that in OSX because I hate using my mouse.
macOS does have keyboard shortcuts, but they do not display with underlined letters. Many menu items will display their shortcut to the right. Some menu items will not have a shortcut.
If the menu item doesn't have a shortcut, you can press Command + Shift + / to open a search bar that will let you type in the command. You can arrow down and hit return to activate that menubar item.
You can also arrow through the menu bar by pressing Control + F2 (or Control + Fn + F2). You may need to toggle this on with Control + F1.