A venue model independent of a team's "stadium" free-text field: it defines the courts or fields by competition, including start times and duration.
Address autocomplete
Via OpenStreetMap Nominatim, which is free and does not require a paid API key.
Schedule conflict alert
The schedule alerts you if two matches overlap at the same venue; it does not automatically generate the schedule to avoid this, but it does flag the overlap so the organizer can resolve it manually.