Yeah I think everyone has to type buddha. Not sure about that though.

for everyone?

Make sure sv_cheat 1 is on.
Then type buddha into the console.
Voila, no fall damage. :)

thx archer do u know about fall damage and how to disable it?

You wanted commands for surfing.
I'll try help
sv_accelerate 200
sv_airaccelerate 2000

and if you want higher jumps
sv_gravity 600 or sv_gravity 500