How do I make apps appear on the taskbar by default?

Please understand that one of the main reasons people often provide commands to run on a terminal, is because it's a lot easier to have you copy/paste a few lines of text, than it is for us to provide a complete walk-through a myriad of menus and sub-menus, icons, settings, drop-downs, etc. Even for simple and routine tasks that could be done in two seconds.

Another reason is because graphical interfaces change from system to system and computer to computer (people like to customize their setup quite a bit), but the commands on the terminal are much more generic.
Incidentally this also means that most of the help you will see online will be in the form of terminal commands, so best to get used to this way of interacting with the system.

You don't have to use the terminal, many tasks are easier to do with a nice point-and-click interface, while others are the opposite. But it comes a long way to at least get comfortable with the basic commands: install packages, update your system, etc.