What should I do when growing my fingernails?

When I grow my nails out, I find that a lot of stuff gets stuck under them.

So, when you remove foreign matter stuck under your fingernails

The slightly scratched part turned white while removing the foreign substance.

It didn't look good. ... It was covered up when I got my nails done, but

I'm not wearing nails right now, so the dirt really shows.

How should I manage this?