"I do not know where I am going to sleep tonight."
Translation:No sé donde voy a dormir esta noche.
I got the same question. I read somewhere (an app called lingodeer) that the future tense is used for more determined things. Like when you say "trabajaré sobre esto" is more like "I will work on that for sure" than "voy a trabajar sobre esto" which would be more like "I will work on that eventually". So maybe in this case, since there is a doubt about where you're going to sleep, you use the form "ir+a" instead of the future tense. Anybody knows if that's the case?
There is indeed a difference. When using it as a question or exclamation, you use the accent. For example: "Where is the meat" is "¿Dondé está la carne?". When it is used in a statement where it acts as a relative pronoun, it does take an accent. For example "The room where I left my meat is clean" would be "El cuarto donde puso mi carne es limpia." It can get tricky sometimes because you can use the form with an accent when it's not a question. It is when it is used as part of a subordinate clause that is interrogative or exclamative. For example: "No sé dónde puso la carne (I don't know where he put the meat)" or "¡Dime dónde está la carne! (Tell me where the meat is)". Another example of this, well, is the sentence above. I actually think it is wrong and should have "dónde" instead of "donde". I would report it but have forgotten how or where to do it when I just follow the conversation. Anyway, the same rules apply to other interrogative words and pronouns such as "cómo/como", "quién/quien", "qué/que", etc. You can read more, in Spanish, here: https://www.gramaticas.net/2016/07/diferencias-entre-donde-y-donde-con.html