To convert Word to Google Docs, upload the .docx to Google Drive, open it in Google Docs, and choose File > Save as Google Docs. This creates an editable Google Docs copy and leaves the original Word file unchanged. To convert every future upload automatically, turn on Convert uploads in Drive settings.
Google Docs can't open .tex files, but you can get LaTeX into a Doc two ways. For a whole document, convert it with Pandoc (pandoc paper.tex -o paper.docx) and open the .docx in Google Docs. For individual formulas, use the built-in equation editor, or an add-on such as Auto-LaTeX Equations to render LaTeX code.
Google Docs has no LaTeX export, so convert in two steps. Choose File > Download > Microsoft Word (.docx) or Markdown (.md), then run Pandoc: pandoc mydoc.docx -s -o mydoc.tex --extract-media=. The .docx route keeps headings, lists, tables, images and equations. Finally, open the .tex file in Overleaf and tidy the formatting.
To insert a PDF into LaTeX, load pdfpages with \usepackage{pdfpages} and use \includepdf[pages=-]{file.pdf} to insert every page as a full page; pages={1-3} takes a range. To place one PDF page as a figure inside your text, use \includegraphics[page=2,width=\textwidth]{file.pdf} from the graphicx package.
To download a large Google Drive file with curl or wget, share it as Anyone with the link, copy its file ID, and request https://drive.usercontent.google.com/download?id=FILE_ID&export=download&confirm=t. The confirm=t parameter skips the virus-scan warning page. Private files need the Drive API with an OAuth access token.
To find a Google Doc's parent folder, click the Move icon (a folder with an arrow) next to the document title. The dialog shows the current location; click the open-in-new-window arrow beside it to open that folder in Google Drive. You can also use File → Details, which lists the document's Location.
