AD7767-2 About to Pin Connections

Hi,

My question would be a very simple question. I'm asking because I can't perceive it because I'm a student.

I intend to connect Raspberry pi with AD7767. However, I can't be sure which data pins of the AD7767 are MOSI, MISO, SCLK and CS. In particular, can MCLK pin be directly connected to pi? Or should I send an input signal with an external clock? (for example: LTC6906CS6)

What is a DRDY pin. What are SO and SI pins? MCLK? and SYNC pin connection required? What are the general tasks of these pins? and why do their names differ in each product?

Finally, are the ADC read limits within the + -1.25V range when the VRef input voltage is 2.5V? or in the range of + -2.5V?

I want to read a signal in the + -2.5V range. How many volts should I drive the VRef pin of the ADC?

Sorry to steal your time for these simple questions.

Thank you so much.
Have a nice day.