Hi Souravdas ,
Thanks for writing in.
Acne is caused by hormonal
Blockage of sebaceous glands causes papules and pustules.White substance is secretion of sebaceous glands.
Acne is treatable now.With correct treatment all your pimples ,
and dark spots can be treated.
To start with you have to apply Aziderm cream twice daily on dark spots .
Also you can use anti acne face wash like actem face wash.
Avoid any hair oil to hairs.Avoid any other moisturizers or cosmetics or home remedies
Use good quality sunscreen like SUNCOTE gel daily while going out.
and glycolic peeling can help you to get rid of acne and pigmentation.
Please visit qualified dermatologist
for giving you specific advise.