Create Data Connection between Google Sheets & Big-Query

I usually create different types of reporting within Google Sheets but since it has a limit for the data inside, sometimes I struggle to build some poweful analysis. I need a 2 scripts created in Javascript, that will create a connection between a Sheet and a Query already built and saved in BigQuery layer. 1 for uploading and appending new information and the 2nd for downloading the results of the query.