Will the game look ok in fullscreen. Or is there at at least an option to just put up black borders in game? Because I have a 24 inch monitor and when I tried to play emperor( a game from the early 2000s) on my desktop it looked awful. (It was fine on my laptop so that's what I play it on) If there is no option in game I can't go into the files myself and change stuff myself because I am HORRID with computers so I just need to know if there is an in game option.

The game's resolution is fixed by default. You can use the HD mod, however.

As for Emperor (assuming you mean Emperor: Rise of the Middle Kingdom, not Emperor: Battle for Dune ;) ), there's an HD tweak as well.

There's no in game option that will help with modern monitors/resolutions, so the HD mod already suggested is your best bet

However It's really as straightforward as it gets: download the installer, when asked choose your existing game folder, and then use the new launcher icon instead of the original one to start the game.

The first 45 seconds of this video shows all you need to do, and can safely ignore the rest:
https://www.youtube.com/watch?v=p4Fct2tfs8I