Note that Google Lens works only when you login with Google account and your device must be connected to a network.
Method 1: touch the “Camera” app -> touch the Google Lens icon

Method 2: press and hold the home button or press Google Assistant Button to enter Google assistant -> touch the Google Lens icon at the bottom of the screen.
Method 3: touch the “Photos” app -> select a photo -> touch the Google Lens icon

When you open the Google lens viewfinder, the lens will continually analyze what you see to show you results in real time. Options include:
1) Translate: Point at text, then tap capture to translate.
2) Text: Point at text, then tap capture to copy or scan.
3) Search: Point at objects, then tap capture to search more.
4) Homework: Point at homework, then tap capture for help.
5) Shopping: Point at items, then tap capture for product details.
6) Places: Point at building for details.
7) Dining: Point at a dish on a menu, then tap capture for details.