RabbitMQ which exchange type to choose for messages?

Question

RabbitMQ

Business logic:
user1 creates an event (event)
user1.....userN send an application for participation in the event (not at the same time, but during the validity of the period before the start of the event)
user1 receives the application from the queue and processes (rejects accepts)
All N users can create events and take part in them. The total number of users of the service> 10k. But in a specific event, the maximum number of participants is no more than 50.

How to correctly implement the interaction scheme, what type of exchanger to choose, is it necessary to create a queue for each user or some one queue and from it, according to some criterion, send a message to the desired user?

Answer 1

A lot depends on the rest of the architecture. For example, what is "userX" from the RabbitMQ side? Is it a direct client connection to RabbitMQ or is the client connecting through some business logic (how many instances)?
Does the client keep a permanent connection to BL/RabbitMQ or make periodic requests to them? Is the data stored in the DBMS? What are the response requirements? How many events/entries per second/minute are expected?