Pick number up ahead (6)
I believe the answer is:
onward
'ahead' is the definition.
(I know that ahead can be written as onward)
'pick number up' is the wordplay.
'pick' becomes 'draw' (I can't justify this - if you can you should give a lot more credence to this answer).
'number' becomes 'no' (abbreviation for 'number').
'up' says the letters should be written backwards (in down clue: letters go upwards).
'draw'+'no'='drawno'
'drawno' written backwards gives 'ONWARD'.
Can you help me to learn more?
(Other definitions for onward that I've seen before include "Advance, Christian soldiers, marching as to war" , "progressive" , "Advance like Christian soldiers" , "Advanced" , "With advancing motion" .)