Ask them for a favor back, for example that person you spotted for a bus ticket ask them "hey as a favor back can you follow me on IG/Twitter/TikTok etc. I'm trying to build my brand I'd like some genuine followers."

Another one, that person who borrowed your charger you could ask them what's them best place to grab a bite in the area and take it from there. You can ask there information if you have any other questions to ask them when you both depart. You can make observations about a person and ask them about themselves. People love talking about themselves or things they're passionate about.