How to do the right architecture?

Question

Software design

Hello! I have activities. Events can be:
1. Different types: battles, master classes, courses, etc.
2. Held in different places and at different venues.
3. Different periods.

One event may include different types, several places and venues in them, and at the same time they can be held with periodicity. However, all this can be one-time. I got something like this scheme . The complete scheme is here .

What are my questions. I need to design somehow the entire domain layer. So far, I have a mess in my head. There are a lot of questions. The domain layer is wider, but so far the questions are only in this area. Questions:
1. How do I design the poster domain? What entities approximately should be?
2. How to make nested events for one event? For example, the event "Competitors of Russia" can take place 5 years in a row, and be held 2 times a year, have 2 venues on each of them 3 sites.
3. A question from a slightly different context. I need to have an association with another "Geolocation" context, namely cities. Will it be enough to remember only the city ID in the context of the event. Or is it necessary to create the essence of the city in the context itself?
4. Since events are in English - Event. Since Events are also called events in the code, I thought about the alternative name Contest. Contest is still some type of event, rather than an event. Is it correct to use this name? Or leave the Event?

If the question goes beyond the scope of the question and is moved to the "Task" section, then I will be glad to hear your suggestions.