IS or IO for a newcomer, and would IH or IO help start conversations?

What are differences. Excuse my ignorance, I’m new here.

Honestly for a lot of people it’s hard to put a finger on.
Both are extremely pleasant and likable. But where IO can create an active, fun chatty type of vibe, Shine is more of a glowing charisma and gives off a vibe that can make people feel good just being around you.

If I have no probably carrying/starting conversation, do you think IH or IO would benefit me?

Depends, YOU being able to start and carry a convo doesn’t mean the other person will naturally be open to it. That’s where IO can help. If you find that on occasion you’re forward and try to talk to people but they’re not very talkative or receptive then yeah a little IO can be beneficial.
If your conversations tend to stay on frivolous topics that may be fun but don’t go much deeper than the casual chit chat among strangers, IH can help escalate the feelings of trust and connection to the point that you find it easier to move the conversation to more serious and/or personal topics.