To start your Phoenix server:

• Set-up env variables for postgres (or go into config/dev.exs and change the fields): POSTGRES_USERNAME POSTGRES_PASSWORD
• Install dependencies with mix deps.get
• Create and migrate your database with mix ecto.setup
• Install Node.js dependencies with npm install inside the assets directory
• Start Phoenix endpoint with mix phx.server

Now you can visit localhost:4000 from your browser.