connecting display with only usb-c ports to macbook pro 2014 (no usb-c ports)
No, you cannot connect the monitor to an USB A port (i.e. for example the non-USB-C USB 3 port you mention).

The monitor uses the so called "Alternate Mode" part of the USB-C connector. Essentially it means that the USB-C cable in addition to USB carries a seperate signal - for example DisplayPort as in this case.

Older USB connectors and cables do not have support for "Alternate Mode" and thus no adapters can be made.