Confuse by suggesting that one should be less calm (8)
I believe the answer is:
bewilder
'confuse by suggesting that one should' is the definition.
'bewilder' can be an answer for 'confuse' (I've seen this in another clue). I'm not sure about the rest of the definition.
'be less calm' is the wordplay.
'less calm' becomes 'wilder' (I can't justify this - if you can you should give a lot more credence to this answer).
'be'+'wilder'='BEWILDER'
Can you help me to learn more?
(Other definitions for bewilder that I've seen before include "Nonplus" , "Confuse totally" , "fox" , "Perplex the wild beer" , "Flummox, confuse" .)