Hello
Brushing with correct technique will help you.
Along with flossing in between the teeth daily.
For tongue coating, vigorously cleaning the tongue won't help,it ll only damage the tongue surface.
Next Steps
Visit the dentist, they ll check for any tarter deposits are present.Also learn tooth brushing technique.Tongue evaluation will guide you whether the coating is because of incomplete cleaning or fungal because of poor oral hygiene.If fungal, topical agents will be prescribed.
Health Tips
Drink enough water.Dehydration or dry mouth is also a cause of bad breathe.