It is well-established that galaxies and their central super-massive black holes co-evolve, which indicates that the growth of a black hole is somehow constrained by its host galaxy and vice versa. Thus the triggering and fueling processes of AGNs are essential to understand the details of the co-evolution. In this talk, I will focus on low-luminosity AGNs, and touch a few aspects of how they are triggered and fueled. I will start by showing intriguing cases where the AGNs might be at their infancies, then discuss how AGNs are triggered or fueled at scales ranging from cosmological large-scale structures to the very central parsecs near the black holes. In particular, I will talk about studies of AGN fueling with 2D spectroscopy. In the end, I will show how future surveys, such as HETDEX, can make significant advances in studies of low-luminosity AGNs at high redshift.