Do I call wides and no-balls?

Mostly no: wides and no-balls are called by the main umpire at the bowler's end. In Stage 1 they're recorded but not re-bowled, and they count towards the batter's balls faced.

Wide: a ball that pitches on the wicket or passes the batter outside their reach in their normal batting position. It isn't a wide if the batter touches it with the bat. A batter can still be run out off a wide. Signal: both arms out horizontally.

No-ball is called if:

• the ball lands off the pitch, rolls off it, or hits its edge
• the ball bounces three or more times, or rolls along the ground, before the popping crease
• the ball passes above the batter's waist on the full
• more than two fielders are behind square leg, or a fielder (including slips) other than the keeper is within 15 metres of the striker
• the bowler knocks off a bail while bowling.

It may also be called if the bowler's front foot lands fully over the popping crease. Signal: one arm out horizontally.

You're best placed to spot too many fielders behind square leg, or a fielder too close to the striker. If you see either as the ball is bowled, call "no ball" and let the main umpire know.