diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2e11006
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+social_security.txt
+private/
\ No newline at end of file
diff --git a/.ipynb_checkpoints/homework-example-checkpoint.ipynb b/.ipynb_checkpoints/homework-example-checkpoint.ipynb
new file mode 100644
index 0000000..e80c2ca
--- /dev/null
+++ b/.ipynb_checkpoints/homework-example-checkpoint.ipynb
@@ -0,0 +1,48 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# This is a markdown"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### This is a heading"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.11.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
diff --git a/README.md b/README.md
index 8956487..b78e52e 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,5 @@ This repository is a demo repository that you can use to practice your GitHub an
 through the online lessons in the [introduction to earth data science textbook on earthdatascience.org](https://www.earthdatascience.org/courses/intro-to-earth-data-science/git-github/version-control/). We will not merge any pull requests here but you can practice opening and closing them here if you want!
 
 Here is some more text.
+
+Today is my learning day.
diff --git a/homework-example.ipynb b/homework-example.ipynb
deleted file mode 100644
index 2fd6442..0000000
--- a/homework-example.ipynb
+++ /dev/null
@@ -1,6 +0,0 @@
-{
- "cells": [],
- "metadata": {},
- "nbformat": 4,
- "nbformat_minor": 2
-}
diff --git a/homework-example_CI.ipynb b/homework-example_CI.ipynb
new file mode 100644
index 0000000..e80c2ca
--- /dev/null
+++ b/homework-example_CI.ipynb
@@ -0,0 +1,48 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# This is a markdown"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### This is a heading"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.11.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
diff --git a/social_security_copy.txt b/social_security_copy.txt
new file mode 100644
index 0000000..4f3f471
--- /dev/null
+++ b/social_security_copy.txt
@@ -0,0 +1,7 @@
+This file will not be included when making version control.
+
+I add another text.
+
+Test.
+
+Haha.