From the first it's daft — it's obvious that it's crazy (7)
I believe the answer is:
idiotic
'crazy' is the definition.
(I've seen this in another clue)
'from the first it's daft it's obvious that' is the wordplay.
'from' indicates anagramming the letters (the anagram comes from the same letters).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'first' suggests taking the first letters.
'that' becomes 'ic' (I am not sure about this - if you are sure you should believe this answer much more).
The initial letters of 'its daft its obvious' is 'idio'.
't'+'idio'='tidio'
'tidio' with letters rearranged gives 'idiot'.
'idiot'+'ic'='IDIOTIC'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for idiotic that I've seen before include "Inviting ridicule" , "Half witted" , "Mindless" , "Altogether nonsensical" , "Witless" .)