Jumping Into a Convo

Being friendly and confident are always the characteristics you should have if you are approaching a group of people that you have never met before. This will make it easier for them to accept you and be more likely to let you stick around in the conversation, rather than walking away.  First off, I would never put my two cents into a conversation unless I did know about what was being said, or I had some idea of the topic. If I'm going to engage in that conversation, I want to make sure I know what I'm talking about and not stutter or have to think about what to say next. Also, I would make sure to listen and be polite while another person was talking because if you cut them off in the middle of their sentence or completely change the subject after they're done talking, that is so rude. Doing this would show that you either don't care about what they have to say, seem as if you already know everything, or just have no idea of what they are talking about in general.
The same things would apply if the situation was switched around, and a random person came up to a group of friends and me trying to talk about the topic. They need to be confident, not cocky, and polite! I am an easy going person as it is so I would have no problem with anyone approaching a conversation I was having with a group. However, if they talked down to me, stuttered and seemed as if they had no idea what I was talking about, or didn;t make any sense of what they were saying, then I would think they were rude and had no clue of the subject. Their opinions would definitely be welcome as long as they weren't biased and had a valid arguement for why they felt a certain way.
Like I said, I am an easy going person, so as long as the approacher was polite and confident, I would not mind their presence in the conversation. Also people should remember to be the same when trying to engage in a conversation with another group.