Hello Hongjin Zeng,
Unfortunately, there is not much documentation on this. What I can suggest is that there is a SampleApplication with PDFs on how to use it included in the MCAL installation. It is the only tutorial to get started. It includes example of most modules like ADC, FlexCAN, etc. However, it assumes you already know how to use the tools.
I don’t have S32K14x MCAL installed, but the sample application is either in the root folder, or in a doc folder located in a similar location as for MPC574xG:
C:\NXP\AUTOSAR\MPC574XG_MCAL4_3_RTM_1_0_0\MPC574XG_MCAL4_3_RTM_1_0_0_Sample_Application\eclipse\plugins\IntegrationFramework_TS_T2D35M10I0R0\doc
Hope it helps,
Mike