Does the Torah mention anything about the importance of volunteering one’s time to their community?
One’s assets, including time, are amongst the many things one can and is required to contribute.
In our liturgy before the Mussaf service on Shabbat and Yom Tov we publicly praise all those who “are involved faithfully in the needs of the community”. This statement reflects the Mishna in Avot 2:2 stating that “All who exert themselves for the community should exert themselves for the sake of Heaven (with pure ambitions), for then the merit of the community’s forefathers aids them their righteousness endures forever”.
In a general sense, all contributions can be viewed as braches of the Torah obligation to give Tzedaka.
It should be noted, though, that we view all activities as means of spiritual perfection. One might devote himself/herself quite selflessly to community and by that hope to attain spiritual perfection, by dealing honestly and wisely with community needs.
Another might choose to “do the minimum” with regard to outward communal activities, and choose the path of personal perfection, including study and prayer.
An individual’s choice should suit his or her individual capabilities and strengths. Ultimately, one should not withhold any of his capabilities from serving G-d.
The creation of individuals with distinct strengths and abilities reflect G-d’s plan for a world full of his divine service in its many facets.