Dear all,
I'm quite new in Amiga CD32...but I always wanted it from my childhood

This is why I'm here with one important question, at least for me, ...is there any fully compatible gamepad from other system with CD32?
I heard about flawless functionality with "
Sega Mega Drive 6 buttons COMPETITION PRO"
But which one? e.g.
Honey Bee SG-18 ?
I already have quite alot Sega other gamepads, most of them are 6 buttons but I'm still worry to try it with my like new CD32
Thanks for any of advice!
You are a bit confused about the competition pro. Rather, the CD32 uses it's own Competition pro gamepad, called the Competition Pro 32, but also sometimes goes by the name the Honey Bee 32. These use the same shell shape as the Mega Drive Competition pro or the Honey Bee SG-18 controllers, but are internally different, and feature different buttons:
If you note, the CD32 has 6 buttons, but those buttons aren't the same as a Megadrive pad, they are unique CD32 buttons. CD32 buttons are labeled by color -- Red, Green, Yellow, Blue, and Left and Right Trigger, and don't map to A,B, C, X, Y, and Z of a megadrive pad. When a CD32 game asks you to press the red button to start, there is no corresponding button on such a Sega pad.
That said, that really only applies to games made specifically for the CD32. There are lots and lots of games made for the Amiga 500 or Amiga 1200 that were merely put on a CD that can run on the CD32, that don't take advantage of the actual CD32 gamepad. Those kinds of games use typical Sega or Atari controllers, but only 1 or 2 buttons. In that case, a Megadrive Competition Pro controller would work with those games, but only the A and B button (and only if the game supported more than 1 button). You could also use an atari joystick, or a master system controller.
Note that there are a few games that were released on the Amiga 1200 late in life, after the CD32 controller had released, that allowed people to use all 6 CD32 unique buttons. Typically the difference between these types of control schemes is denoted as Joystick (1 button), Gamepad (2 button), and CD32 Pad (6 buttons). Games like Fightin' Spirits are like this.
For the most part, you'll probably want a CD32 pad, just for universal compatibility. CD32 pads can also function as 2 button or 1 button controllers. The stock CD32 controller blows, IMO, but I rather like the competition pros 32s. Recently, there has been a DIY controller that people are fitting into SNES controller molds that seems like overall the best controller around, though. It has all 6 CD32 buttons, but also lets you use a built in remapping feature to change controls, so like if you want jump to be on a button and the game only uses up on the dpad to jump, you can move jump to a specified button. You can find people selling those controllers on this very forum.
EDIT: Forgot that the CD32 pad has a start/pause button, so it's 7 buttons overall, but otherwise all my points stand.