My scalp itch and when i check my nail there's white & black its not lice is this normal? what is it?

Possible fungal infe: There are many causes of itchy scalp, esp dandruff and seborreic dermatitis. White stuff suggests dandruff or skin scales, but could be pus from small pimples or folliculitis. Black is less common, and may be dried blood from scratching or hair roots damaged by a fungal infection (ringworm, tinea capitus) and is associated with a patch of hair loss. Oral Rx is needed for that. Start with exam.