I want to go to Tokyo Racecourse or OI Racecourse

I want to go to Tokyo Racecourse or OI Racecourse

1. Do I need to book tickets in advance?

2. Would I be able to bet on horses even though I don't speak Japanese?

3. Which of the two (Tokyo Racecourse or OI Racecourse) should I go to?

4. Is it open on weekends? at nights? etc.