Start eagerly but find you can go no further (3,5,2)
I believe the answer is:
get stuck in
'further' is the definition.
Both the answer and definition are verbs in their base form.
Perhaps they are linked in a way I don't understand?
'start eagerly but find you can go no' is the wordplay.
I cannot really see how this works, but
'find' could be 'get' (synonyms) and 'get' is found within the answer.
'you' could be 'u' (commonly used in online communication) and 'u' is located in the answer.
'no' could be 'n' (common abbreviation) and 'n' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for get stuck in that I've seen is " Concentrate on your work!".)