I would like to get a Inspiron 7000 with Ryzen 2500U. I just would like to know if it supports 3 monitors with a USB-C dock?
Yes, but only if you plug one monitor into the laptop's display output itself. I have my Matebook D running a 3440x1440 monitor via HDMI, a 1920x1080 monitor via a USB-C dock (Which supports two), and the built in 1920x1080p laptop monitor.