There are 9 innings in college and MLB.
There are 7 innings in high school.
Either can go into extra innings in case of a tie.
In Texas, High School baseball games are 7 innings long, and I believe that is the same around the country. If the game is tied at the end of the 7th inning, it continues until there is a winner.
There are 9 regulation innings. It can go into extra innings if the score is tied.
If the score is tied after 9 innings, it is played until one team has a lead after a full inning. Games are suspended, per baseball rules, at 2am local time and continued later that day.
7 innings for most high schools
MLB consists of 9 innings, more if needed to determine a winner, less if non post season game and inclement weather delays the game.
You are confusing baseball with soccer. The duration of baseball game is measured in innings. A soccer games is measured in minutes.