Visiting Chicago for the first time

Braves fan here, and planning an early August trip to Chicago to watch a few games. I searched through the sub to get tips for visitors (thanks for the food suggestions), but I was also curious about transportation to/from the park. Where I'm staying I'll have access to the red line train, and as far as I can tell, it goes straight to the park. I'm curious about availability of trains, how far in advance I need to get to the park to buy tickets and get to my seats, and whether or not I should use the train or go the Uber/Lyft route to get to and from the park. I know essentially nothing about the neighborhood, so all help is appreciated.