Manage appointments

Hi guys, how are you?
I want to ask you if you have some guide related with scheduling appointments. Right now I’m working on a project that has to schedule appointments for mentors and students. While doing some research I found that many begginers developers (like me) are facing the same problem , related to the time slots and how to block them to prevent other users to make the appointment on the same day/hour whith the same person (tutor, dentist, doctor, room, etc). There is not a lot of resources for begginers on this topic. If you have some, with implementation examples, would you mind to share it ?
I found some packages like django-scheduler and also django-swingtime , but I’m struglling on how to implement that because the only info I found is their documentation.

Modoboa, a python/Django email server has an app to display calendar from Radicale Calendar server.
Also I found to be nice but with a dependency to a paid service.
I’d like to remove that dependency and make it work with Modoboa/Radicale.