Hi,
You don't mention what body you have, but you already have the lenses you need.
In short: Take the 35 and the 50. Set them at f2.8, Av mode, set ISO as needed and shoot like a maniac........
Well, let me explain a bit......
Outdoors in a park, the 50mm is perfect. Find some shade to avoid harsh sunlight. If overcast, that's even better! Set aperture to f2.8 for individuals or the couple. This aperture will provide small but manageable depth of field with nice out of focus background. Always focus on the eyes of the subject and recompose if needed. Of course for group shots you need smaller apertures depending on the size of the group. f8 is a good starting point for group shots.
Use the lowest practical ISO but beware of shutter speed chosen by the camera.
You don't mention external flash but if using it, beware of sync shutter speed. An ND filter may also be helpful outdoors.
For the reception, the 35 may be more practical if indoors. Again, f2.8 to f8 work great. For indoors, depending on what body you have, the ISO can be bumped to keep shutter speeds relatively high and minimize motion blur.
But most importantly: Have fun!
Thanks,