Correct style of creating low level diagrams

I am practicing low level design diagram and would like the community feedback on how Low level design should look like.

Note: this is more from interview prespective because I checked few websites like educative.io and wasn't convinced with their approach. It seems like business logic is merged into classes which also contains DB tables mapping.

Lets consider an example of drawing a low level design for a parking lot. The first diagram is what I have come up with the and the second one is from educative website.

First: The most important feedback I am looking for is which is the correct style of drawing LLD.

Second feedback : if we want to search for a book based on location and availability ( essentially if I have to join few tables to get a result ) which repository should handle this job bookRepository, bookItemRepository, bookingRepository. In my example I have given this responsibility to bookRepository.

Third : When to use Repository and when to use Dao. Are my repositories correct or I should have used DAO

Below is the functional requirement ( I don't think it will make a difference as my questions are almost agnostic of Functional requirement)

• User: can search a book/reserve a book/
• Admin: can add/remove boook My Solution
  

educative.io solution

NOTE: I understand educative.io has more complete diagram my question is more from style of drawing LLD and separation of concerns .