How do I see the pages that most visitors landed on? How do I access the top pages people use before leaving the websites?

Matomo reports Pages URLs and Page Titles. You can see the Top Entry Pages by clicking on Behaviour > Entry pages. By default, it shows the top Entry Page URLs, but you can switch to the Entry Page Titles by clicking on the “Related report: Entry Page Titles” link below the report.

Similarly, you can access the top pages that people see before leaving the sites, click on Behaviour > Exit pages. It lists the “worst” Exit Pages URLs by default, but you can access the top exit page Titles by clicking on the Related reports link below the table.