Basic midi editor query

I’m new to Cubasis and have never used Cubase or any DAW before. I want to set all the notes in the midi editor to the same velocity and duration without having to do each one separately. In the midi editor I double click to select all the notes but when I slide the bars at the bottom for velocity or duration the values change but all the notes retain their relative difference. Am sure this must be so simple to do but the instructions in Cubasis are so short they don’t seem to cover it. Very grateful for any help

for velocity select all drag down to zero and go from there - works over here.
the same goes for length drag left and go from there.
mind you i’m using the edit buttons on the left hand side of the piano roll!

Thanks for your support, mm70!

@ helivesmylife
Please follow this link to have a look at our available MIDI editor tutorial:
https://youtu.be/H9urz7bCSaI

Best,
Lars