Help with registers

Hi there,
I am struggling really hard! I have prototyped this on an Arduino Uno in Arduino IDE and everything is working great. But now I am trying to port everything to an Attiny1614 and I don't know how to make these registers work for the Attiny. I have searched up and down the datasheet but I have no idea what im doing, ive never done registers before. Can someone please help me find the equivilent register settings for the Attiny1614? I would seriously appreciate it!

// Set ADC to 77khz, max for 10bit
    sbi(ADCSRA,ADPS2);
    cbi(ADCSRA,ADPS1);
    cbi(ADCSRA,ADPS0);

Attiny1614 Datasheet:
http://ww1.microchip.com/downloads/en/DeviceDoc/ATtiny1614-data-sheet-40001995A.pdf

Arduino Uno (Atmega328p) Datasheet:

Read section 30.3.2.2 Clock Generation on page 480.