You can continue using a mouthwash on a daily basis, rinse well with the mouthwash after meals and brush twice a day with an extra soft toothbrush and a toothpaste. The yellow in the teeth isn’t going to reduce with the toothpaste/mouthwash. You will need to do a round of cleaning, may be bleaching and if need be you can go in for Veneers.
Next Steps
Continue maintaining oral hygiene and visit a dentist for a round of scaling to start with.