Should I use all the pins from 1 Port or few from each available (STM32)?
The pins that can be used by the SPI, I2C and interrupt hardware might constrain your selection of pins.

The layout of your board might also influence the pin selection.

For (relatively) high output currents (generaly not a good idea IMO) some chips have a per-port limit, which would favour choosing pins for higher current outpust from different ports.

(copied from Jeroen3's answer) When you are very current-starved it might be good to disable unused ports, which can favours using pins in already used ports.

When you must quickly copy a multi-bit value to a number of pins, it will be much easier when those pins are on one port (and even easier when they are conseqeutive and start from bit 0).

Other than those aspects, I don't see how it makes any significant difference which pin you choose, from the same or different ports.