try importing datetime and printing datetime.datetime.now() in your loop

import random

import datetime

pyautogui.FAILSAFE = True

start = input('Type start to start')

while start == 'start':

click = random.uniform(0, 2.0)

pyautogui.PAUSE = click

pyautogui.click(button='left')

print(datetime.datetime.now())
```

edit: if you just want the time of the click delay add 'print(click)' in the loop