You are at Lower Shing Mun area, you could round route to visit the reservoir, Hueng Fan Liu or connect to other trail
https://www.hklii.hk/eng/hk/legis/ord/102/
https://droneandslr.com/travel-blog/hong-kong/lower-shing-mun-reservoir-hike/
https://www.alltrails.com/trail/hong-kong/north/lower-shing-mun-reservoir-loop