Use the environment file sample to create your own. Most likely you can just copy it verbatim.
From a terminal, run
docker-compose up
Once running, you can view the site by visiting http://127.0.0.1:32733
This can be done in the docker compose yaml file.
Changes to the environment need to be made in the Dockerfile and this should then be tagged as an appropriate image name for the project in the docker compose yaml file.