combine cells and delete duplicates

I am working on a list to send out holiday cards, however, I only want to send 1 holiday to card to each address. In many cases I have a husband and wife at the same address 1 holiday to card to each address.

Please the attached example, in many cases I have a husband and wife at the same address (see rows 3 and 4 - Agnes and William Mutert). How can I combine the first names into 1 cell so that on husband and wife cases, it would be Agnes and William?
Also, want to delete duplicates, for example rows 20 and 21 - Margaret Brueck. Only want to send 1 holiday card to herm not 2.

Any help would be greatly appreciated. I am not sure if there is a formula or formulas that I need or if I have to do it all manually. I have about 6000 entries, so anything would be helpful.