Hello,
You won’t be able to create the multilingual site without the third-party plugin.
WPML is the plugin that allows you to make your site multilingual. You need to install plugin, follow the setup wizard and add your languages. Then you need to translate hardcoded strings of theme or plugins (using String Translator) and translate your content (posts, products, pages). If you speak FR, EN, ES you can do this by yourself, if you don’t then you need to hire the person who will be able to do this for you.
Regards