RH.

Set your camera to apeture priority and shoot
the same subject with every F stop
your lens is capable of. Should be a dozen
or so setting from around 4.5 to 22.

Notice that at a wide open setting like 4.5
Only the subject is in focus, while at a small aperture like F 22 both
Foreground and background are fully in focus.
Shooting lots will help lots.
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No huevos no pollo.