@melka I’ve got some free resources to help you learn and think about how to create this (data structure, some copy-able elements, etc), and also a plugin that works to help tie it all together. You can check it out here: TopCal Plugin
The trickiest part with this type of setup is the Search and Filtering, especially if you have a lot of Calendars/Accounts that need to be searched.
I describe one way to do this here: Searching for "who's available" (I'm using TopCal plugin)
But if there are a lot of Calendars/Accounts to search through and you would want to optimize the search UX over other areas of your app, then you may want to save every available vs booked time slot directly on the calendar’s instead of running a Free/Busy workflow on every Search