Create a new calendar event
On signing up for the first time, everyone gets a default Personal calendar in Scrims. This personal calendar is suppose to hold your private events, or those you are interested in or going to on other community calendars, or your personal availabilities for people to know when you're available or busy.
If you want to connect your personal calendar events with an external calendar you can do so via the integrations settings, note that you can only connect Primary google calendars with Personal calendars.
There is no harm in using Personal calendars to host your public events if you don't want manage multiple calendars for hosting events. However, because your personal calendar will also have events that you're going to, it is recommended to use a new community calendar to host public events that others can discover.