On a Mac with Catalina you can open your iPhoto Libraries in Photos. Photos will create a Photos Library from the iPhoto Library.
First you have to restore the iPhoto Library from your backup disk to your Pictures folder. Is your backup a Time Machine backup? Then use Time Machine to restore the iPhoto Library (not the iPhoto.app) to your new Mac.
Now launch Photos while holding down the options key ⌥ and release the key when you are seeing the dialog to select a library. Select your old iPhoto Library from the list of libraries. Then wait for Photos to create a Photos Library from it. The new Photos library will be created in the same folder as your iPhoto Library. You should be finding all phots and videos in the new library, also the albums. The Events will be converted to albums.