That's probably enough of the theory: let's get Moodling.
I'm assuming that your Moodle admin has already given you your username and password (maybe it is simply the same username and password you use to access other services at your establishment). Let's take those and get logged in...
Go to your Moodle site's front page and look for a link that says Login. It depends on how your Moodle site has been 'themed', but good places to look are in the bottom-middle or the top-right of the page (if you definitely can't find the link then speak to your Moodle admin). Click on the Login link to open the login page:
2. Type your username and password into the relevant text boxes and press the Login button.
3. Enter your username OR your registered email address into the boxes provided. Press the OK button. You will be sent an email detailing how to log in.
4. That's it! You're now ready to Moodle!