In the time of the Torah, the command was to eat matzah, maror (bitter herbs) and the Passover sacrifice on the first night of Passover. After the destruction of the Temple in Jerusalem, when it was no longer possible to bring the Passover sacrifice, the original command ceased to be relevant. Based on this there would be no special obligation to eat any of the above on Passover. Rather, there would remain only the prohibition against eating leaven.
However, another command on the Torah that states "eat matzahs at night" teaches that even after the destruction of the Temple there is still a Torah mitzvah to eat matzah nowadays. In addition, the Rabbis institued a command to eat bitter herbs to remember the bitterness of slavery. The Passover sacrifice cannot be brought in any way due the lack of the Temple.