32-bit iphoto app - how do I access my old photos?

Your photos will not be in the iPhoto App - iPhoto managed your photos in an iPhoto Library. The first thing to do will be to find your iPhoto Library. By default it has been stored in your Pictures folder, unless you have moved it somewhere else. Look for an item with an icon like this:

As Yer_man explained, you have missed the chance to to create a Photos Library from your iPhoto Libraries.

do you still have an older Mac where you can create Photos Libraries from your iPhoto Libraries? If not, consider to downgrade temporarily back to macOS 12 Monterey, until you have migrated the iPhoto Libraries to Photos. Otherwise you will not be able to save the albums, titles, keywords, adjustments and can only transfer the original photos by importing each iPhoto Library into a new, empty Photos Library.

iPhoto was discontinued 7 years ago. It is no longer developed or sold. It was replaced by the more powerful (and free) Photos.app that comes with the OS. Migrating from iPhoto is quite straightforward:

With versions of Photos prior to v8 (released with OS Ventura) you simply open the iPhoto Library with the newer app. It does the rest.

With v8 it is different. You can import images from the iPhoto Library, so you can be selective about what you import, and can consolidate images into a pre-existing Photos library.

If you prefer not to use Photos there are several 3rd party apps that you can use. Which to choose depends on the kind of photographer you are and your budget.