The "look" being acheived in those engagement shots has a lot more to do with the quality of light and lens choice. You cant "post produce" quality of light.
Dylan is correct that VSCO film packs were likely used to get the tinting. Applying those filters to shots that dont have good light quality wont replicate what you see in those engagement photos though.
Light, light, light and then light again. Thats the key. Then lens, exposure, composition, subject, emotion etc etc...post production is the very last thing...by a huge margin...that you should be thinking about to "replicate" the look of those photos.