To share a document in your email:
Upload to Google Drive: Upload your document to Google Drive by logging in and clicking "New" > "File Upload".
Get Shareable Link: Click the 3 dots next to the uploaded file, select 'Share' the 'Copy link'.
Include in Email Template: Paste the copied link into your 'thank you for enquiry' email template.
For detailed instructions on email template setup, refer to: How to setup email and amend templates.