Playcitizen's Code of Conduct
Invitations = RSVP - don't just ignore an invite. If you're not interested or not available press X to decline the offer to meet up. If someone declines your invite, don't take it personally. Just keep reaching out to others until you find your match.
So you found each other and set up a time and place to meet. Good sport etiquette means you arrive on time and ready to go. If you have a last minute delay or worse have to cancel - send a message right away.
As much as a great workout or amazing walk is affirming, if you enjoyed the match, don't forget to find ways to develop friendship. Go out for a coffee or drink after with your newfound friend.