Can I turn off Digital Crown fully for example during training sessions because it’s realy embarassing that, the Crown sometimes stops the session if I accidentaly push it :(?

I don’t think there’s a way to disable the Digital Crown.

You shouldn’t be accidentally pressing the crown during a workout. That tends to suggest your watch band might be too slack and the watch is moving too low on your wrist, or your workout has something pushing up your forearm (risk of damage to the watch). You could see how it feels with the band one stop tighter, or move the watch so the crown is on the side away from your wrist during the workout (either move it to the other arm or turn the watch around).

Pressing the Digital Crown, either intentionally or accidentally, during a workout does not terminate the workout. It merely returns the  Watch face to the previous screen. To get back to the workout you need to tap the workout icon. I keep the workout icon as a complication on my  Watch face. If you do that as well, should the Digital Crown get pressed you can easily get back to the workout by taping on the icon for the workout app.

1. Press and hold the side button until you see the Power Off slider.
2. Drag the slider to turn off your device.
3. When you want to reactivate your watch... press and hold the side button again until you see the Apple logo