Good morning Hy, Sentence 1 is correct, however, normally 'you are' would be shortened to 'you're' in a conversation. The word 'If' at the start of the sentence implies uncertainty; the person will not watch TV in every outcome, it depends on the finishing of homework. Henceforth, we wouldn't use will here, because it implies certainty. 'Will' implies that the person will finish their homework in every outcome, and will watch TV in every out come. I hope this helps, Tom

The first seems better to me. "going to" works better for conditional sentences using "if" and "then"