In order to use the LocalExecutor, you need also need to upgrade your database by using MySql or Postgres. I recommend :

1. Using postgres : Create a db dedicate to airflow (like : airflow_db), create an user and grant him all control on this db

2. pip install psycopg2-binary and pip install apache-airflow[postgres]

3. Configure airflow.cfg ( sql_alchemy_conn = postgresql+psycopg2://:@:/airflow_db)

4. start db server

5. launch : airflow standalone