After you serve in padel, the point is not finished by the serve itself. The serve starts the movement that follows. Your next job is to move forward and join your partner rather than stay behind on the baseline.
If the serving player stays back, the pair can become split between defence and attack. Moving forward together makes the first volley easier to cover and gives both players a clearer shared position.
What to do
Think of the serve and the next movement as one action. Serve, recover your balance, then move toward the net with your partner. You do not need to sprint blindly, but you do need to avoid becoming the only player left deep.
The key is arriving connected. One player at the net and one player deep creates a large space for opponents to use. Two players moving into the same attacking shape are much harder to play through.
Why it works
The simple rule is: after serving, look to join the net. If the return puts you under pressure, react to the ball, but your default intention is to move forward as a pair.
That gives you a repeatable pattern: serve, move, get connected, then play the next ball from a stronger position.