Appropriate timing for implants (question)

Each of your molars on both sides is missing one.

One was seven years ago, the other four years ago... I believed that Lee Hana was born and didn't take care of her, and I had never even been to the dentist before removing her wisdom tooth, but as I got older, I really felt that sending Lee Hana away was so upsetting.

Is it usually okay to delay getting an implant after a tooth falls out? There are also scary stories that the upper teeth will grow into the empty space of the lower teeth and need to be shaved down later.

Since I haven't received proper care and a tooth has fallen out, I need to take care of it now, but currently, I am just consistently brushing my teeth well.

It still seems too early to ask about overall costs, methods, or materials.