In Mark 2, what was the name of the tax collector Jesus called from his booth?

Answer: Levi

Mark says Jesus saw Levi son of Alphaeus sitting at the tax booth and told him, "Follow Me," and Levi followed.

“As He was walking along, He saw Levi son of Alphaeus sitting at the tax booth. “Follow Me,” He told him, and Levi got up and followed Him. After this, Jesus went out and saw a tax collector named Levi sitting at the tax booth. “Follow Me,” He told him,”— Mark 2:14; Luke 5:27 (BSB)