If your match is scheduled for a certain time the proper thing to do would be to arrive at least 10 to 20 minutes prior to your match. But if you come just on time that is fine also. That is not the same however if you are late. The rules are that every 5 minutes you arrive late you lose 1 game (which will be explained later on). If you are 30 minutes late you lose 1 set (which will be explained later on). If you arrive 1 hour late you are disqualified (both will be explained).

Starting at 0 or "love" one player must win four points, called 15, 30, 40 and game.

If the score is deuce (40 to 40), the game continues until one player wins by two points. The advantage point , then the game point. If you lose the advantage point, the score returns  to deuce. 

The first competitor that wins 6 games win the set, but the winner must be at least two clear games in front. If in a set reaches 5-5, play seven games. If it is 6-6 play first to 7 points (tiebreak), and whichever player wins the tiebreak win the game and set.

A match is usually the beat of three sets ( five sets in men's professional matches).

When you play friendly or junior tournament matches, you usually make your own line calls. Judge as best as you can. If the ball lands out then call it right away. If any part of the ball lands on the line, it is in. If there is a line call disagreement, then play the point again. this is called let (second chance). 

The first serve of every game is taken from the right side of the court. Stand behind the baseline and serve diagonally so that the ball lands into your opponents right service box. Alternate from side to side. Each player serves for a full game.