Pain in the testis and groin has no relation to feet .
Pain in the feet can be due to plantar fascitis.Your shoe or sandal heel should be high.Take anti inflammatory drug if the pain is severe
It is natural that one testis is at higher level than other.
Groin swelling can be inguinal hernia
Please consult a surgeon and get an ultrasound
and inguinal region and proceed accordingly
Wish you good health