Makes one's mark as a newcomer (5,2)
I believe the answer is:
signs on
'makes one's' is the definition.
The answer and definition can be both to do with social activities as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
'mark as a newcomer' is the wordplay.
I cannot quite understand how this works, but
'mark' could be 'sign' (synonyms) and 'sign' is found in the answer.
'as' could be 'so' (I've seen this in other clues) and 'so' is found within the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for signs on that I've seen before include "Hires" , "Employs" .)