How many serve attempts does each player get per point in beach tennis?

Two. Each player gets a first serve and, if the first serve is a fault, a second serve. If the second serve is also a fault (double fault), the receiver wins the point. A let does not use up a serve attempt.

Full Explanation

Per ITF Beach Tennis Rules Rule 7, each server has two opportunities to put the ball into play per point: the first serve and, if a fault occurs, the second serve. If both the first and second serve result in faults (a double fault), the receiver wins the point. A let on either serve (e.g. net cord landing in the service box, receiver not ready) does not count as a fault and the relevant serve is retaken. This is identical to the service rules in standard tennis. In the golden point at 40-40, the server still receives two serve attempts.

Ruleset: ITF  |  Rule Reference: ITF Beach Tennis Rules, Rule 7 (The Service)