A wide overhead shot of Citi Field prior to the first pitch in a game between the Pittsburgh Pirates and New York Mets.
The Top of the First Begins
It’s the top of the first inning, there’s nobody out. The first batter (sometimes referred to as the "leadoff batter") comes up to the plate, to start a "Plate Appearance," which just means a batter coming up to bat. This term is sometimes used interchangeably with something called an "At-Bat", though the two are not technically the same; depending on the result, a plate appearance may or may not be an at-bat1. No matter what you call what happens next, the batter approaches the plate, and the game is ready to begin.