Yogurt Vs. Milk

Weight loss is about having a calorie deficit. What you eat to get there is just your preference.

Greek yogurt+granola+frozen peaches is an amazing breakfast, however.

For me I use yogurt. The lowest in fat or zero fat Greek yogurt and least amount sugar and the highest in protein. Example: Chobani Plain Greek Yogurt Fat 0 Sugar 9 Protein 23.
Calories 100 for 8oz.

For weight loss, count calories.

There's a wide variation in calorie counts for different brands, varieties, and portion sizes of milk and yogurt both, so it's going to depend on that. Two different yogurt varieties can vary in calorie count by 100% for the same portion size, for example.

Just eat what you like, read labels, and measure portion sizes.

Ew, yogurt not from an individual package but from a communal vat with a ladle, probably covered by a sneezeguard? Honestly, if it were me, my answer would be right there. But if that doesn't bother you, normally I think a dining hall would make the nutritional info available to you if you ask politely for it.

Still though. Eat the food you like. Don't get all hung up on tiny differences as though one choice is magic somehow. If you can't read labels, educate yourself about the general basics, make an average guesstimate, move on with your life.