Selenium in Python: find element after a click

I need to build a find and click procedure, step by step, but I'm not able to do it.

My starting code is:

from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.common.by import By
driver=webdriver.Firefox()
driver.implicitly_wait(2)#seconds 
driver.get('http://mywebpage.com/page')
# The browser open page1
wait = WebDriverWait(driver, 2)
confirm = wait.until(EC.element_to_be_clickable((By.XPATH, "(//a[@class='button_serv'])[4]")))
confirm.click()
# The browser open page2 in the same window

Now I would like to find an element in page2, but the driver points always to page1 (because my code is wrong):

wait = WebDriverWait(driver, 2)
confirm = wait.until(EC.element_to_be_clickable((By.XPATH, "(//a[@class='button_serv'])[9]")))
confirm.click()

How to tell to selenium to wait and search fon content of page2?

Thank you