I don't understand how to use MAESTRO to control SongSelection and Delay

Hello (I am using BeatBudy Beta 4.3.1 / Aero Beta 5.0)

I have just started to look into MIDI and possibly I would buy MIDI MAESTRO. But the following two points are not yet clear to me:

  1. MAESTRO as a MIDI controller means to me that to select a song on BeatBudy I have to send the following commands:
    CC:0 Value 0-127
    CC:32 Value 0-127
    PC Value 0-127
    Where can I find out in Beat Budy which values of CC0:, CC:32 and the PC command is assigned to a song stored on Beat Budy?

I have the Delay Replika from T-Rex with MIDI jack. From the manual I take:
CC20: Contains the tempo of the delay.
CC21: Turns on and off the delay
More is not in the manual. Maybe it is not necessary, because it is the following standard?
Replica receives on channels 1 to 16 because nothing is specified?
The value CC21 0 is for switch off, because nothing is specified?
The value CC21 1 is for switch on, because nothing is specified?

Thank you very much if you can help me.