how do I select photos to store in my library on a computer if I don't want to pay for icloud?

See -> Transfer photos and videos from your iPhone or iPad to your Mac or PC

Transfer photos and videos from your iPhone or iPad to your Mac or PC - Apple Support

Here are 2 options for you:

• Plug your iPhone into your computer and import the pictures into the Photos app on your Mac.
• AirDrop the photos from your iPhone to your Mac

This link should help...

Transfer photos and videos from your iPhone or iPad to your Mac or PC - Apple Support