One of the easiest ways to express the future in Spanish is by using the irregular verb "ir" plus one more verb in its infinitive form (termination in -ar,-er,ir) This grammar is quite similar to the "be going to" form in English.
Yo voy a viajar a México mañana.
(I'm going to travel to Mexico tomorrow.)
To form the negative you use need to add the word "No" before the verb "ir" conjugated.
Yo no voy a viajar a Mexico mañana.
(I'm not going to travel to Mexico tomorrow.)
If you want to make questions in this form you just need to place the questions marks (¿?) at the begining and the end of the sentence. In speaking you need to use some sort of raising intonation. Very similar to the one you use when asking questions like Do you like coffe? in English.
Affirmative: (Ellos) van a tomar un táxi.
(They are going to take a taxi.)
Question: ¿Van a tomar un táxi?
(Are they going to take a taxi?)