The word "behold" alerts us to a new group in the story. Your language may have a way of doing this. AT: "there was a crowd that appeared" (See: [[rc://en/ta/man/translate/writing-participants]])
"to greet him with a kiss" or "to greet him by kissing him." When men greeted other men who were family or friends, they would kiss them on one cheek or both cheeks. If your readers would find it embarrassing to say that a man would kiss another man, you could translate it in a more general way: "to give him a friendly greeting." (See: [[rc://en/ta/man/translate/translate-unknown]])
Jesus uses a question to rebuke Judas for betraying him with a kiss. Normally a kiss is a sign of love. AT: "it is a kiss you are using to betray the Son of Man!" (See: [[rc://en/ta/man/translate/figs-rquestion]])