You definitely want to focus on example 5 of The Serial Input Basics tutorial which presents the idea of how to parse the received data using strtok().
The tutorial material on how to receive the date is not really relevant to the Ble Uart Friend as the filling of the received ble.buffer is done with
ble.println("AT+BLEUARTRX");
ble.readline();
Forming your data with separators to enable easy parsing is what to focus on along with the techniques to convert the character inputs into the numerical input required by the FastLED code.