* English fans block park's central opening - goodness! (5,4)
I believe the answer is:
barmy army
'english fans' is the definition.
I know nothing about this answer so I can't judge whether this works.
'block park's central opening goodness' is the wordplay.
'block' becomes 'bar' (bar is a kind of block).
'park's central' becomes 'yarm' (I can't explain this - if you can you should give a lot more credence to this answer).
'opening' is an insertion indicator (some letters open a gap in others).
'goodness' becomes 'my' (both are exclamations of surprise).
'yarm' placed inside 'my' is 'myarmy'.
'bar'+'myarmy'='BARMY ARMY'
Can you help me to learn more?
(Other definitions for barmy army that I've seen before include "England's travelling supporters" , "English supporters (like 26)" , "team supporter" .)