You’ll admit the town centre has everything (5)
I believe the answer is:
allow
'everything' is the definition.
I can't judge whether this definition defines the answer.
'you'll admit the town centre' is the wordplay.
'you'll' becomes 'alow' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'admit' is an insertion indicator.
'the town' becomes 'ely'.
'centre' says to take the centre.
The middle letter of 'ely' is 'l'.
'alow' enclosing 'l' is 'ALLOW'.
'has' is the link.
Can you help me to learn more?
(Other definitions for allow that I've seen before include "Permit or agree" , "Permit, consent to" , "praise no more" , "Licence" , "Acknowledge - concede" .)