How do I "ssh into sites directory"?

I'm fairly new to Laravel, but I did manage to get my site up and running on Digital Ocean using Forge. But then my git repo got a little messed up and I'm no longer able to deploy changes. The deploy error reads

"error: Your local changes to the following files would be overwritten by merge: .env Please commit your changes or stash them before you merge."

The Forge docs explain:

"Please Commit Your Changes Or Stash Them Before You Merge

This error occurs when files within the site directory have changed and will be overwritten by the fresh deploy.

To fix this, you should SSH into your sites directory and run:

git reset --hard && git clean -df

You should also take a look to see why files in your project have changed."

Here's my problem: I can ssh into my server, but I don't see anything in the files that would accept git commands. Presumably, I've misunderstood what the docs mean by "SSH into your sites directory." Can someone help me understand how I should proceed?

Thanks in advance.