If I had to guess, I'd say you're either in the wrong directory, or you're missing one or more components you need.
First, make sure you're in the correct directory. You'll know you are because you'll see an sfdx-project.json file.

If your Explorer doesn't look like this, verify that you're in the correct directory. In your command shell, try dir /s sfdx-project.json
and use the correct directory:

Switch to that directory and run Code from there.

After that, you can verify if your org is properly connected in the lower-left corner:

The plug icon should show your org's username or alias (here, sfdcfox
). If this isn't right, click on the plug icon and choose the correct org (or you can authorize a new org).

Now, this specific error suggests that your force-app directory is empty. Make sure your files are in the right place:

If it doesn't look like this, there's a problem. Also, double-check your sfdx-project.json file, it should be exactly:
{
"packageDirectories": [
{
"path": "force-app",
"default": true,
"package": "DreamhouseLWC",
"versionName": "Summer '21",
"versionNumber": "53.0.0.NEXT"
}
],
"namespace": "",
"sourceApiVersion": "53.0",
"packageAliases": {
"DreamhouseLWC": "0Ho3h000000PBghCAG",
"DreamhouseLWC@50.0.0-1": "04t3h000004skyPAAQ",
"DreamhouseLWC@50.0.0-6": "04t3h000004slZvAAI",
"DreamhouseLWC@50.0.0-8": "04t3h000004sla5AAA",
"DreamhouseLWC@50.0.0-11": "04t3h000004slorAAA",
"DreamhouseLWC@50.0.0-16": "04t3h000004sm0nAAA",
"DreamhouseLWC@50.0.0-22": "04t3h000004sm5nAAA",
"DreamhouseLWC@50.0.0-26": "04t3h000004sm67AAA",
"DreamhouseLWC@50.0.0-28": "04t3h000004smaYAAQ",
"DreamhouseLWC@51.0.0-1": "04t3h000004smn8AAA",
"DreamhouseLWC@53.0.0-1": "04t3h000004VW48AAG",
"DreamhouseLWC@53.0.0-3": "04t3h0000043sQIAAY",
"DreamhouseLWC@53.0.0-5": "04t3h0000043scGAAQ"
}
}
If it doesn't, try pulling down the repository to get the latest changes (note to future visitors: if this changes, feel free to modify this answer or let me know).
In summary, make sure you're connected to the right org, make sure you're in the right directory, make sure no files are missing, etc. I did verify that this is working (the modified file deployed successfully), so it is likely something you've done incorrectly. Try cloning a fresh copy of the git repository and try again, paying close attention to which directory the files are cloned in to.