I have a TB16 Docking station, that I use with my Dell Latitude and it works great.
This is the one I have Dell Business Thunderbolt Dock - TB16
No, this won't work. The TB16 requires a Thunderbolt 3 connection to the laptop. It is not backward compatible with anything else. Intel recently released an updated Thunderbolt 3 chip meant for peripherals that would allow them to be backward compatible with USB-C with reduced functionality, but the TB16 doesn't have that chip. But dropping all the way down to USB 3.0 wouldn't be feasible because only USB 3.0 ports can't have GPU outputs wired to them like USB-C and Thunderbolt 3 can, so you wouldn't have video. There are some docks that support video over USB 3.0, like the Dell D6000, but they achieve that with DisplayLink chips, and that technique has some significant drawbacks that I've explained in this thread, specifically the post marked as the answer.
For dongles, there are no dongles that would allow you to attach a Thunderbolt 3 peripheral to any other port, even Thunderbolt 2. There aren't even any "official" dongles to allow you to attach a USB-C peripheral to a USB-A port either. Some manufacturers provide them with certain products because they know their USB-C device will work properly even when connected via USB-A, but they aren't "official" because not all USB-C devices will work over USB-A. There are however dongles to allow you to attach a USB-A device to a USB-C port, since that always works.