To edit plugins, click on the jigsaw icon at the top, then edit the parameters that says 'Font' and 'Font Filename' to the font that you want to use. Download the zip and put it inside the plugins folder of your project (Documents > Games > js > plugins).
In order to install a plugin, the creator will often include a zip file with the. If you use MV, you can change it with Galv's Message Style plugin. Thanks to this piece of code, you can have any font you want in the game and it will appear in every of the game's text. Click on it and replace all text with the following code included in this Pastebin. To do it, click on the button and scroll all the way down until you see something called Main. But there is an incredibly easy way to change it. Let's be honest, the default font for RPG Maker is ugly.
