Log in to edit your site at www.yourdomain.com/wp-admin. For security purposes, this address is often customized to a unique URL that will be provided in training.
You can customize the home dashboard screen to optimize fields for your most common tasks. Your dashboard preferences are unique to your account and don't affect how the rest of your staff uses the site. For more info: https://codex.wordpress.org/Dashboard_Screen
The Dashboard navigation menu is at left. For lots more info on specific menu items: - https://codex.wordpress.org/Administration_Screens
The Help Menu is a red button in the top right of the screen, with tips & info that changes depending on which part of the site you're editing.