If the weather is beautiful, talk to them about the weather. Weather is one of those topics that can help you easily start a conversation with anyone. Start with something like, I think it's going to rain today, what do you say? Indulge them in small talk that should not make them anxious or overwhelmed.
When you meet someone for the first time, leave a good impression by greeting them warmly. Smile when you talk and appear friendly. Introduce yourself. If you have known their name and forgotten it, politely ask them again. Open up to them and ask them what they do and where they live. Try to connect but don’t ask personal questions or make fun of them.