to prevent osteo, you need more calcium in your diet, this is
very important if you plan on consuming high amounts of
protein.
to build mass, you might need to up your calories, especially
protein to aid muscle
growth.
do exercises like squats, dips, chinups, any compound excercise
will help, just make sure to train all parts of body, it will help
you reach your goals sooner.
btw , what i said may not be fully correct, im still consider
myself a beginner in this field 
