This snippet is a great starting point for your work with this dataset. Visit the Sentinel-2, Level 1C page and see Explore in Earth Engine section to find the code snippet to load and visualize the collection. Search for the Sentinel-2 Level 1C dataset and you will find its id COPERNICUS/S2_SR.
You can load a collection by searching the Earth Engine Data Catalog for the ImageCollection ID. An ImageCollection is a dataset that consists of images takes at different time and locations - usually from the same satellite or data provider. Most datasets in Earth Engine come as a ImageCollection.
