1
On your keyboard, look at the function keys (F1 - F12), if one of those keys has an icon like a touchpad with a line through it, try pressing that key or Fn + that key to check if that enables the touchpad on your laptop.
2
If that does not resolve the problem, the best option would be to go to the support page for your laptop on the Lenovo website to download and reinstall (not update) the version of Chipset drivers and Touchpad drivers they provide.
If you have any difficulty locating that support page, click your Start Button, then just type msinfo and press Enter, please provide a screenshot of the resulting System Information window.