Mate, you are said to be in as novices (8)
I believe the answer is:
amateurs
'novices' is the definition.
(I've seen this in another clue)
'mate you are said to be in' is the wordplay.
'you are' becomes 'ur' (textspeak abbreviation).
'said to be' becomes 'as' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'mate'+'ur'='mateur'
'mateur' going into 'as' is 'AMATEURS'.
'as' is the link.
Can you help me to learn more?
(Other definitions for amateurs that I've seen before include "Dilettantes" , "Tamer USA (anag.)" , "Non-professionals" , "They're enthusiastic" , "They play for love of the game" .)