Good listening and speaking skills are needed to have a conversation.
A conversation rule is: Do not speak when someone else is speaking. Listen and wait till the other person has finished speaking.
If you have to interrupt like you have to rush to get to another commitment say:
"Excuse me for interrupting but I have to go. I will talk to you later."
What are some ways of introducing yourself?
"Hi, my name is … and your name is?"
"I am pleased to meet you."
"Do you often come here?"
How do you keep a conversation going?
Ask them a question about a topic you both have in common:
"Do you often come here to …?"
"How has your week been?"
"Do you have a big family?"
"How many siblings do you have?"
"What do you like to do on the weekends?"
"What do you do as a job?"
"Do you have any hobbies or interests?" If they pick a common hobby or interest too, say, "I like … too."
Finish off the conversation with, "It was nice chatting with you. I hope you have a nice (morning, afternoon, day, evening)."
If the person mentions something strange or awkward, say, "sometimes strange things occur."
If the person apologises for something, be gracious by saying, "that is okay, mistakes happen."
If the person offers you advice the polite response is, "Thank you for the advice, I will consider that."
If the person tells you that something is making them sad, say, "Yes, you're feeling sad. I understand."
To make a friend, you must first be friendly.