Hi @elinamirin,
If you are reporting on the entry page you should use both the Entry Page dimension and the Page Name dimension in different reports, as both will give you more useful information and will work differently with specific metrics, which is more insightful than just using one alone.
If you use the Entries and Visit metric with the Entry Page dimension this will show you the same data, as the visits metric in this case is just the number of visits that started with that page.
If you combine this with the Entry Rate metric you will just see 100% for each dimension value, which doesn't tell you anything on the performance of the entry page.
The Average Time Spent on site, the average time spent on the site where that page was the entry page.
(Average time spent on site has a misleading title it's actually the average time spent interacting with the dimension value, so with the Page Name dimension it's just the average time spent on that page).
Now if you use the Entries and Visits metrics with the Page Name dimension, this will show you the same number for the entries as the entries and visits you see with the Entry Page dimension but when you use the Visits metric with the Page Name dimension you will see the number of visits to that page. You can then use these along with the Entry Rate metric and you get more useful information on the performance of the page from than just using the Entry Page dimension alone.
Some metrics are the same in both and it doesn't matter which dimension you use for example Bounces are the same across both dimensions as is Bounce Rate.
In short, you should for some metrics it doesn't matter what you use but it does for specific ones. If you want some clarification on if a metric is suitable, the description you see when you click on the info icon of the metric will usually be enough to tell if it's correct to use it or not.