The words for day and year are somehow special in that way, they don't use 下 and 上. It's 明年 and 去年 instead of 下年 and 上年, as well as 明天 and 昨天. Other time-related words like month and week do use 下 and 上.
《会》 can be used for several grammatical functions, here it's is being used to indicate a future tense as "will". Place 《会》 before most verbs and it will usually mean a soft "will". Other words can be used to emphasize the importance of the future such as 《一定》 and 《得》.
Basic Chinese sentence structure goes: Subject + Adverb + Verb + Complement + Object. In this case, the indication of time would be in the adverb slot. You're sentence is legitimately incorrect, but I'd use this opportunity to grow! 我为你加油！
But I don't think 明年 should be placed right at the end of a sentence. Chinese sentences are set out differently but not too different. Duo just wants to make sure you learn and know the proper words and placements of where words go.