string stringTakenFromDiscord = "play *songname*,*channelname*";
String[] input = stringTakenFromDiscord.Split(',');

//input[0] will be equal to what comes before the comma
//if you were to print it, it would be "play *songname*"

//input[1] will be  what comes after the comma
//if you were to print it, it would be "*channelname*