Free Lancers + Events

I want to create a system (or use a ready one) to manage events and the assignment of employees to each event.
My employees are not constant workers, they are more like freelancers that pick the events they want to work at.
What I need that on the creation of an event, all of the relevant (let’s say I need two dishwashers and two BBQ boys) employees will be announced and will be able to apply to the event, and I’ll be able to confirm/not confirm.
In the frontend of the employee, I’ll need a calendar that shows all of the next events
I am posting this post to make sure there isn’t an existing plugin/code before I begin to develop my own.