Dentists are following strict covid protocols. Don't worry about that. Visit in early morning hours, when the patient load is less and the instruments are freshly sterilised.
But the cause of swollen gum and a swollen lymph node needs to be assessed before anything else. Seems like an affected tooth or gum infection (periodontitis)
Health Tips
For oral hygiene, A good colgate/pepsodent toothpaste may do and use stim floss. A mouthwash like listerine or Hiora will be of added benefit. Tongue cleaning with a regular brush will keep the mouth clean.