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.

Going to Tokyo next week, here's our itinerary:

Day 01 - arrival (afternoon), shibuya, donki , and golden guy

Day 02 - Disneyland

Day 03 - tsukiji market, temple, and teamlab

Day 04 - mt fuji, and ski

Day 05 - free day or harry potter

Day 06 - Free day/Departure (night)

Just wanted to ask if there are any non-obvious things we should take note of?

edit: I'll add some more information.

We'll be travelling in a big group (16+) and we'd prefer to not move hotels.

The itinerary is kind of empty because we'd probably spend a longer amount of time than usual in every spot because of how big our group is.

Personally, I prefer food, some sightseeing, and shopping (thrift and souvenir shopping) which I'll probably do on the free day. (I was thinking somewhere along the lines of Shimokitazawa?)

I'll add:

~~1. Are there any Horse Racing Tracks where we can watch near Tokyo? (is it open on weekends?) ~~ I found Tokyo Racecourse and OI Racecourse.

1. Do I need to book tickets for the Horse Race Tracks ahead of time?