Is there any shortcut to add Ped for all chord at one?
No, I’m afraid not. I think it’s worth saying that for the purposes of a human playing the music, all you need to do is indicate the first couple of uses of the pedal, and then write “simile” thereafter. Or you could even simply write “con pedale” at the start of the music. Of course, Dorico doesn’t know how to pedal the music automatically in the way a human would, so if you need pedaling for the purposes of playback, your best bet is to add it in the automation lanes in Play mode, by adding points for CC64.
Can I play the score and I hold sustain in my foot under each chord to add it as c64?
Yes, you can record in pedal changes in real-time.