Question on power consumption on S32K1xx
Source: https://www.nxp.com/docs/en/data-sheet/S32K-DS.pdf
In short the chip will consume power depending on:

What peripherals are enabled
Current consumption of peripherals (use high impedance if possible)
What clock speed chip is running at

The clock speed pf the S32L142 is determined by the PLL (and if you select an internal or external oscillator, it has an 8Mhz low power oscillator built in, or you can use  an external oscillator from a range of 8-40Mhz).  The S32L142 will then consume power at roughly 400uA/MHz, so the lower the clock speed the better power consumption (less switching of transistors is usually lower power in most digital devices). So set the PLL lower (which is configurable by software).
The S32L142 also has a low power mode, which uses a 128kHz internal oscillator. so if you can put the processor to sleep, it will use very little power.

Suppose, I use this 8MHz resonator between the pins 11 and 12, how to
determine the current consumption due to this resonator?

The power consumption will be determined by the clock frequency of the SPLL (configurable by software) and then the s32 will use roughly 400uA/Mhz
EDIT:
This is a much better diagram for your questions and the clocks in use, the document below also shows code on how to switch power modes on the S32k1xx

Source: https://www.nxp.com/docs/en/application-note/AN5425.pdf