I'm a semi-pro photographer and I use Lightroom. For me, the $9.99/month price for Lightroom and Photoshop combined is well worth the price. It's important to note that Lightroom isn't just an organizer, but it's also non-destructive photo editing software, so that protects your images as well.
That said, if you don't want to pay a monthly subscription, here is a 2021 article reviewing Lightroom and alternatives.
https://www.digitalcameraworld.com/buying-guides/best-photo-organizing-softwareAside from which software you use, there's also the question of how you protect and organize your photo collection. Here are a few recommendations.
1) When you upload photos to your computer, make a copy to a separate, external hard drive and don't edit or delete images from that hard drive. That's your back-up.
2) My primary photo file structure is date-based, with each day's photos also have a descriptive name. Then, each photo gets a file name that includes the date, something descriptive, the original photo file number, and something relating to the status of that photo in terms of whether and how it's been processed. For example:
I recently did a photo shoot of rescued momma dog and her puppies. I uploaded those photos to a file folder like this:
2021 (the year's photos)
- Folder: 2021-11-05 Sunny and puppies
- Sample file names: Mouse-211105-3648-O and Mouse-211105-3750-O (i.e. Mouse the puppy, photographed on Nov 5th 2021, the image files out of the camera were numbered 3648 and 3650, and "O" stands for original (the original RAW format file I uploaded). If I edit File 3750, then I will have variations like 3750-L (edited file, full size), 3750-W (web-ready file that is smaller size and easy to upload and with a copyright notice), 3750-IN (formatted for Instagram) and 3750-P (print-ready: means I have processed this file to optimize it for printing and have actually printed it and am satisfied with the print quality), 3750-P-1x1 (this means it's a print-ready file that has been cropped to a 1x1 aspect ratio).
3) Because I use Lightroom, I can create virtual collections of images based on tags etc so I don't need to create multiple folders to hold the same images. I can also attach stars to my images, so I know which photos are the best in a series, and then I can search based on those stars and other tags.
4) I have 3 main back-up hard drive collections:
a) The original photos I took, straight out of the camera, organized by date - not touched.
b) Year-to-year collections (e.g. 2020, 2021)
c) Greatest hits collection. Every 6 months or so, I search for the best photos taken in the prior period, and upload to a separate hard drive the Original (unedited) image, the "L" file (Large, edited image), and the "P" file (Large, print-ready image). These photos are organized in subject matter folders (e.g. Farm Sanctuary).