Do I need to meet people face-to-face?
That depends on the nature of the item(s) or service(s)...
For example, if you are meeting the need of someone who asked for a prayer partner, you can probably just do this over the phone without ever having to physically meet. If someone is in need of help with painting one of the rooms in their house, chances are you’ll have to meet face-to-face. Or if you are just shipping items (i.e. laptop, toys, clothes, etc.), there is no need to meet. If you are providing or receiving transportation services, you’ll probably have to meet.
It’s ultimately up to the two parties (giver/receiver; buyer/seller) to arrange things in order to acquire or provide the posted item(s) &/or service(s).