1) I am going...: Voy...
...to go out...: ...a salir...
...for dinner.: ... a cenar. (Lit. to eat dinner)
2) You are going...: Vas...
...to obey.: a obedecer.
3) I am going...: Voy...
...to lie.: ...a mentir.
4) We are going...: Vamos...
...to share.: ...a compartir.
As you can see, the construction relies on your knowledge of the conjugations of ir and the infinitive forms of the verbs you need to complete the sentence, which can be found in a dictionary.