it is clearly a first winter. Regarding its sex, I think it is too early to tell as this bird definitly haven't started moulting into breeding plumage, and I'm not sure that their sex can be told in their first winter plumage...
Other difficulties with 1st Winter birds is that depending on when they are born (first or second clucth) they can show a lot of variability from an individual to another due to their age and this is also explaining why the period they start moulted into breeding plumage vary a lot as well...