I would advise against writing to excel as your primary DataBase in 2021. If you’re interested in it as a backup data source or to just learn, it may be reasonable.
I have a few old games that do this, and the data has stood the test of time. This tutorial from woot3 is more or less how I handled it. Note that the module provided is no longer supported.
The biggest thing you’re likely going to run into is that Google Sheets has infinitely harsher quotas than DataStoreService. Any game that scales players heavily will almost certainly hit this quota resulting in data failure - where a certain amount of retries is just adding pointlessly to the stack.