Underside of my tongue and lower front bottom gum teeth are slightly sore and feel raw(few days). light smoker -havnt smoked recently. whats wrong?

Many possibilities: Could be gum infection, viral invasion, trauma, burn, draining abscess, or even cancer from smoking. Please see a Dentist for an evaluation.

Sore tongue & gum: Impossible to diagnose without a clinical and visual examination. Make an appointment to see a dentist.

Hard to say...: Without being able to look at your teeth, radiographs, knowing when your last dental exam and cleaning was, or even your age, the best advice is to see a local dentist who can actually see you and provide needed services, if any.