I have several questions before I try to offer any guidance:
1. Are you already familiar and comfortable with Outlook calendar?
2. Is the Google Calendar you're trying to manage your own, or does it belong to someone else or another entity and you've been granted modification permissions?
3. Am I safe in presuming, at least at the moment, that you are trying to use the Google Calendar web interface to create/edit events/appointments?
Google Calendar's own web interface has changed, not like last week recently, but within the last year, so that a minimal set of features for an event, not including notifications, is shown by default. You must activate the More Options control in order to have the full complement of event options, including the Notifications controls, become visible. There are only two Notification methods, email and notification. Email is exactly what you'd think, an e-mail is sent to you to remind you at whatever interval prior to the event you set. Notification will cause a pop-up on a desktop computer or a notification message on a smartphone that's much like a text, but generated by Google Calendar.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
The purpose of education is not to validate ignorance but to overcome it.