Crystals are “good enough“ for many applications without any tuning. Typical accuracy might be between 10 parts-per-million (ppm) and 50 ppm.
That’s what you’ll get on your Nucleo board.
If you need better accuracy and/or stability for example when making test-equipment or narrowband radio, then you need to compensate for changes in crystal characteristics over temperature with a “Temperature Compensated Crystal Oscillator�? (TCXO). Such oscillators burn more power than the “basic�? crystal oscillators that stm32 are designed for.
Crystals are much better than internal oscillators, which even with calibration struggle to achieve accuracy of 1% (10000 ppm) and even that’s just at one temperature!
