You cannot use the monitor as a fully-fledged docking station. With the USB-C port, you can connect your laptop to transfer data and provide up to 15W of power, but that's not enough to charge a laptop or provide all the functions of a docking station. The screen, keyboard and mouse will work if you also use the appropriate cables and connectors, but the USB-C port does not support video transmission and provides little power.
For video transmission you have to use HDMI or DisplayPort. The USB hub function allows you to connect your keyboard and mouse to the monitor, but the USB-C port is only intended for data and limited power supply.
The "P2725H without stand" monitor is VESA-compatible, which means that it can be used with VESA-compatible stands. The Dell P2719H monitor also has a VESA mounting surface of 100 mm x 100 mm. Therefore, the P2725H should fit on your old Dell stand from the P2719H as long as it is also VESA compatible. However, it is advisable to check the exact VESA dimensions of your stand to ensure that they match those of the monitor.