Hit a Deer, fek me. Ive been riding bikes since 1980 and the nearest animal strike was an Owl that dive bombed me one evening
Anyway, Ideally a chain and sprocket set should be bought together, so the worn sprockets do not prematurely wear the new chain. But if the bike is only a year old and probably 3-5k miles eh, and you say the sprockets are perfect then you will get away with just fitting a new chain.
You dont have much (anything) in your profile so I'm guessing its a 125, if so it'll probably have a split link on it which makes it a piece of piss to swap over. Remove the split link on the auld chain and join your new chain to it then just pull it through so your new chain is in position. Discard the auld chain and split link, fit the new link with the closed end facing the direction of travel, adjust the slack, oil it up and away you go