hopefully this fixes it

client/public/index.html

@@ -39,5 +39,6 @@
       To begin the development, run `npm start` or `yarn start`.
       To create a production bundle, use `npm run build` or `yarn build`.
     -->
+    <script src="//code.jquery.com/jquery-2.1.3.min.js"></script>
   </body>
 </html>

client/src/App.js

@@ -0,0 +1,17 @@
+import { BrowserRouter, Routes, Route } from "react-router-dom";
+import Hero from "./components/Hero";
+import Header from "./components/Header";
+import Home from "./components/Home";
+function App() {
+  return (
+    <BrowserRouter>
+      <Routes>
+        <Route exact path="/" element={<Header />}></Route>
+      </Routes>
+      <Routes>
+        <Route exact path="/" element={<Hero />}></Route>
+      </Routes>
+    </BrowserRouter>
+  );
+}
+export default App;