Getting started with Google Sheets
Indenting within cells in Google Sheets
Unlike Excel, Google Sheets does not currently allow you to indent text within individual cells. You can, however, accomplish this using a Google script. Please see the article below for instructions on how to install a script to enable indenting.
Linking formulas between Google Sheets
In Excel, it is possible to include in a formula a reference to a cell in a separate file. This is not possible in Google Sheets.
However, you can create a workaround using the ImportRange function. The ImportRange function creates a copy of the referenced data in the referencing Sheet, and the copy live-updates from the original. You can then point to the imported copy in a formula as you would any other cell.