Hi Lyneece
If you want to use "Core" features, you can add the "Main Menu" block to your frontpage: https://docs.moodle.org/403/en/Main_menu_block, and then add "Page" activities into this -- these will live at the 'site' level and be accessible to all.
If you want to try a plugin, give the Static Pages plugin a try: https://moodle.org/plugins/local_staticpage - this lets you create HTML pages that live 'outside' of a course and you can define who has access to it.
More info here: https://github.com/moodle-an-hochschulen/moodle-local_staticpage/blob/master/README.md
More info here: https://github.com/moodle-an-hochschulen/moodle-local_staticpage/blob/master/README.md