Where can I find a video to understand how to use iPhoto?

First, I am wondering where I find a video to understand how to use iPhoto? 

Yous sure this question is about iPhoto? This:

My question is inside "My albums" I have iPhoto events,

sounds more like Photos, the app that replaced iPhoto. Can you confirm?

As a general rule, albums in both apps work the same: they are ad hoc groupings of images based now whatever criteria you prefer.

Albums reference images in the Library. Deleting images from an album, do not remove them from the Library.

When you migrated your iPhoto library to Photos all of your events were converted into albums in Photos. Here are some screenshots to show you what happens:

Here are some user tips from Photos for Mac  User Tips that will help you in your transition from iPhoto to Photos:

How to prepare the Photo Libraries before upgrading to Catalina - Apple Community ➙ read first  if you haven't already upgraded to Catalina

Notes on Migrating an iPhoto Library from iPhoto to Photos for Mac 

External Editors in Photos Are Here

Photo Editing Extensions for Photos for Mac

Post 9/30/2018 Printing Options for Photos - Apple Community

Ordering Books and Calendars on a Mac that cannot be updated past El Capitan 

Use Project Extensions to order print products in Photos after September 30, 2018 - Apple Support

Create and order print products in Photos with Project Extensions - Apple Supports

Since you've already migrated the first link won't be of much help.

The folder "iPhoto events" is, how the events from your iPhoto library have been saved, as albums. It is the only place, where you can find the names of the events you created in iPhoto or the projects you created in Aperture.

To delete a folder with albums inside, ctrl-click or right-click the folder in the sidebar, then select the command "delete Folder". The folder and all albums inside will be deleted, but the photos will remain in the library. This will get rid of all albums at once.

As to the videos, there are a few tutorial videos provided by Apple Support on Youtube. You may want to search this site for "Photos": https://www.youtube.com/channel/UCYFQ33UIPERYx8-ZHucZbDA/videos