In Washington, Boys and Girls High School Tennis falls in either the Spring season or the Fall season (also known as the "Alternate" season). At some schools, the Boys and Girls teams compete during the same season whereas at others one team competes in the fall and the other in the spring.
The Washington Interscholastic Activities Association (the "WIAA") has rules and regulations that set out when the season officially starts and ends, required number of practices before athletes are eligible for match play, maximum number of matches (or "contests") vs other schools, etc. Information published by the WIAA about the 2024-25 and 2025-26 school years can be found here.
Although school-hosted and/or coached practices are not allowed (per the WIAA) to start before the first official day of the season, many teams have "Captains' Practices" that are organized by the student athlete team captain(s), and are a chance for the players to get together and practice and socialize without coach involvement.
Once the regular season starts, there is usually a week dedicated to tryouts for Varsity and Junior Varsity teams. Once Varsity and JV team rosters are settled, most schools practice every day after school, except when they are hosting or traveling to play against other school teams (or when the weather doesn't cooperate). Most teams play a variety of Conference and Non-Conference matches with only the Conference matches counting towards the team official standings for the season. Often schedules are coordinated so that when one school's Varsity team is hosting another school, the other school's JV team is hosting the first school's JV team.
The Division/Class determines how many matches constitute a "contest". For instance, in 3A each team vs team contest consists of 4 singles matches and 3 doubles matches. The team that wins the most matches is victorious. At most contests, exhibition matches are usually played once the "counting" matches have finished, to give more players match experience. Players are encouraged to cheer on their teammates as they compete.
Often graduating seniors are recognized and celebrated at the last home match of the regular season, although traditions vary from school to school.