I recommend starting with Memrise. You can quickly build a strong vocabulary by working flashcards sets anytime you have a spare moment, and it has an app for mobile use. The more words you recognize, the easier it is to understand what is being said or written. Grammar and building sentences should come later, and is best done within an active community where you can get interactive feedback.
A mother was walking hand-in-hand with her young daughter. The girl tugged on the mother's jacketed arm and pointed at me. "Look mommy, a man on a bicycle!" A man. Was I a man? No, I was that kid people mistake for a teenage employee at department stores. The kid whose ID get squinted looks when buying aerosols, who can't buy PEGI-18 without an interrogation. Men are old. Not like me.