system
A chat on subreddit /r/NoStupidQuestions
human
You don't add cream to a latte because it's already mostly a milk drink.  There are various flavors of a latte, most popular is vanilla.  If you ask for a vanilla latte, they will use a vanilla flavored syrup and as such, it's already sweetened.  When ordering espresso drinks, some places will ask how many shots you want.  So this is the coffee to milk ratio.  2 or 3 shots is normal.  Also clarify the size.  Also might be good to specify "hot" since some places do iced lattes. In the drive through it will automatically be to go, but in person might need to clarify. Of course the cashier will clarify all these things if you don't, but since you said you didn't wanna wing it, I'll try to just give you a sentence that answers all their questions. 

"Hello, I'd like a 12 oz, double-shot vanilla latte, to go, please."
gpt
Thank you, this is helpful.