Calendar formatting. Creating a multiple year with automatic fill in based off inputed information

I want to create a calendar for my office, where I can make it once and everyone else can use it. And they understand how to work it

I need a calendar where people can request leave time off and by inputting it in one tab it will automatically populate to the correct spot on calendar.
I also need to create a weekly calendar that pulls the info from the monthly calendar.

If you have any clue how to assist thanks ahead of time