Does osteopenia always lead to osteoporosis? Please, need some answers?

Nope. Hi. No, osteopenia is a RISK for osteoporosis, not a GUARANTEE of osteoporosis. Treatment to preserve bone health can prevent progression to osteoporosis. Adequate calcium & vitamin D help, but alone are generally not adequate to prevent progression to osteoporosis.
Not always. Decrease caffeine intake, quit smoking, increase calcium and vitamin D in diet, and do weight bearing exercise daily to try to decrease progression.