ex) Threre are some roses there.

I think the first 'there' is different from the second 'there'.

The second 'there' is an adverb of place.
What about the first 'there' What is the term for the first 'there'?

The first "there" is simply introductory; it's not really serving any purpose, such as an adjective or adverb or whatever. The second "there" is an adverb, yes.

=)