"Do you want to introduce yourself?"
Translation:Vill du presentera dig?
Would not "Vill du presentera sig" work as well, since it would point back to du? It was not accepted.
sig is for pointing back to somebody in third person singular; dig is always used for second person singular. So it would be vill hon presentera sig? for instance.
Are they used pretty much the same way as in English? Like you present an idea and introduce people to each other?
Yeah, there's a large overlap just like in English, but that's the general gist of it. Maybe the overlap is actually a little bigger in Swedish as well.