Has the sacrificial system of the Torah been abandoned? Do those in the Tribe of Levi still act as priest?
I have just never seen or heard of anyone making sacrifices of animals or going to a Tabernacle as it is described in the Torah.
The Torah made it very clear (Deuteronomy 12:5-18) that once the Jews would reach "the rest and inheritance ...the place G-d will choose" (i.e. the Temple in Jerusalem), that would be the place for sacrificial service. The Second Temple was destroyed by the Romans around the year 70, and thus there haven't been sacrifices since. Thus, many of the roles of the Levites (and the Kohanim, a subset of them) haven't been available for quite some time.
There are a few ceremonies today still performed, however, though none as dramatic as animal sacrifice. A Kohen is given some money to "redeem" a firstborn male child, and a lamb to redeem a firstborn male donkey (okay that one isn't quite as common). Kohens and Levites are still accorded special honors in synagogue service (e.g. getting called up to the Torah first), and participate in blessing the people as described in Numbers (6:22-27).