Friend for social walks

We would love a doggy friend for our 5 year old, super friendly, male (castrated) labrador. Ideally we could meet and just go on a walk around the block, go somewhere to sit while the dogs interact etc.

We would like this to make our dog happier and provide him with a friend but also to calm him down a bit with other dogs (he is a bit reactive- in a joyful way!)