With dialog boxes, I find that you usually have two options:
"Cancel", "disagree", "No, go back" - an option to close the dialog box without performing an action.
"Agree", "Yes, I'm sure" - an option that performs the intended action.
I've always thought you should present the action first "yes, I'm sure" followed by an option to cancel "No, go back". However, looking around there seems to be conflicting ways of presenting this.
One of the reasons I feel like the action should be first (left) as it is the first thing the user will read and therefore be the primary action you want them to achieve. Although considering mobile, the primary action wants to be as close to the thumb as possible so you would want to present it on the right [I realise this is favoring right-handed people].