We can’t afford a photographer

What types of cameras are you looking for? Are you looking for a DSLR/professional camera? Or point-and-shoot digital camera? Or single use film cameras? You may be able to rent cameras through a camera/photo store.

If looking for a professional/advanced camera, are you confident that your guests will know how to use it properly? Would you plan to have someone keeping track of all of the rented equipment to ensure nothing gets lost, stolen, or damaged? Are your guests aware ahead of time that you'll be asking them to photograph your wedding?

If not, I don't recommend relying on guests to capture photos/videos of your wedding, as it causes them to have to "work" your wedding instead of enjoying it as a guest, and they might not capture the types of photos you're looking for. Instead, you could check with the photography department of a local college or university to see if any photography students are available to capture your wedding. This is often cheaper than booking a professional, and the photos could still be excellent quality.