Yes, LEARNER is a Scrabble word!

Letter values in Scrabble US: L 1, E 1, A 1, R 1, N 1, E 1, R 1.

Is it a valid word?

LEARNER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

someone (especially a child) who learns (as from a teacher) or takes up knowledge or beliefs
works for an expert to learn a trade