Two things that will help: Talk about stuff that excites you. That enthusiasm is contagious and others love being around someone like that. The other thing is to pay very close attention to others & listen to them and be interested (probably easy for an introvert). People like feeling like someone cares about what they have to say rather than always talking about themselves.
People like being around a positive, happy, enjoyable person who smiles and laughs often, someone who isn't negative or talks about negative things-complaining, gossiping, etc.