If you're doing something in a place, use で. 家でハンバーガーを食べた。 I ate hamburgers at home. Direct objects use を. If there is no preposition in English, chances are it uses を. Not every case, but often.
'Become' is a special verb. If you are showing a change into something, you should use に for the resulting noun-state, it is a directional marker of sorts. イチゴをジャムにしました。 that's a second sentence with a similar usage of に.
2 is fixed where Toritribe mentioned, but I would correct the second half as well. ねむたく means 'want to sleep' in the adverbial sense. ねむい means sleepy, so ねむく would be a more direct translation.
Toritribe is the expert though. If he corrects anything I've written, trust him over me.