"Go to" is used when you want to say where you are going to. Example: go to work go to school go to bed go to church go to town go to court And "go for" is used when you want to express the activity you're going to pratice: Example: go for a walk go for a beer go for a ride go for a surf go for a drive Did you get it?

-Go for a retreat. -Go to a temple. These are correct. 'go to' is used when you are going to a place. Temple in this case 'go for' is used when you are going for a purpose. Retreat in this case. Retreat is just time taken away from your usual duties for a short time. So it's not a place but it's something that you do. Alternatively this is also correct. -Go to a temple for a retreat. Go to/for a temple retreat is not correct. But it is acceptable. But strictly speaking you should try to avoid it.

"go for a temple retreat" says that you are going there to get away from other things (these things could be a busy job or people) "go to a temple retreat" just says you're going to a temple retreat. That is, you are going to a place that is away from civilisation.