Moodle is a Virtual Learning Environment. It (can) cover every aspect of teaching, learning and educational management.
My suggestion would be to:
- Start by describing every detail of your existing educational process, from listing and advertising courses through to marking and certification/graduation
- Then decide which of these steps should be done with Moodle
- Then use Moodle documentation, youtube videos, etc to match your steps to Moodle concepts and terminology
- Then determine if the core Moodle functions are sufficient, or if you need a plugin to get a better fit between your requirements and Moodle processes (for many users, it is the wide range of plugins that makes Moodle attractive)
Step 4 is best done by actually installing Moodle. a free MoodleCloud account will be fine to get started, but you cannot install plugins there. For that, you'll either need to pay, or install Moodle on your own server.
Once you have a Moodle set up, create accounts for admin, teacher and student and get comfortable understanding the roles, facilities and workflows for each type of user.