I am a student and I have a spreadsheet which has all of my upcoming assignments. I know that skills can connect to an API, is there any way I can get Alexa to read the last line from my Google sheet?
The Google Sheets API has Node.js support, which is a common language to write Alexa Skill handler functions in. So what one could do is write a skill in Node.js hosted on AWS Lambda that performed the necessary calls to Google Sheets to retrieve what you need. It's a bit of work, but not extreme and would be a great learning opportunity.
Look around and you might even find some Alexa Skill projects that already do things similar to this.