Excel - multiple locations from Googlemaps to give distance and time

Hi,
I'm a complete Excel novice and downloaded the document attached somewhere from the internet as I need to find from just over 20 locations, which one is closest to one other location using googlemaps. The data from the spreadsheet is great but I also need to know how long it will take as sometimes one person may be closer to the main location but (for what ever reason) another person may be further away but time wise it's quicker.

Any help would be greatly appreciated and hopefully what I've said makes sense!

Thanks,
Vicki