Error while checking out during "Exercise - Add unit tests to your application"

[Arranic]

Received the following error while running Step 2 from "Fetch the branch from GitHub":

terminal command: git checkout -B unit-tests upstream/unit-tests
error: The following untracked working tree files would be overwritten by checkout:
.gitignore
.vscode/launch.json
.vscode/tasks.json
LICENSE
LICENSE-CODE
README.md
Tailspin.SpaceGame.Web.sln
Tailspin.SpaceGame.Web/Controllers/HomeController.cs
Tailspin.SpaceGame.Web/IDocumentDBRepository.cs
Tailspin.SpaceGame.Web/LocalDocumentDBRepository.cs
Tailspin.SpaceGame.Web/Models/ErrorViewModel.cs
Tailspin.SpaceGame.Web/Models/LeaderboardViewModel.cs
Tailspin.SpaceGame.Web/Models/Model.cs
Tailspin.SpaceGame.Web/Models/Profile.cs
Tailspin.SpaceGame.Web/Models/ProfileViewModel.cs
Tailspin.SpaceGame.Web/Models/Score.cs
Tailspin.SpaceGame.Web/Program.cs
Tailspin.SpaceGame.Web/SampleData/profiles.json
Tailspin.SpaceGame.Web/SampleData/scores.json
Tailspin.SpaceGame.Web/Startup.cs
Tailspin.SpaceGame.Web/Tailspin.SpaceGame.Web.csproj
Tailspin.SpaceGame.Web/Views/Home/Index.cshtml
Tailspin.SpaceGame.Web/Views/Home/Privacy.cshtml
Tailspin.SpaceGame.Web/Views/Home/Profile.cshtml
Tailspin.SpaceGame.Web/Views/Shared/Error.cshtml
Tailspin.SpaceGame.Web/Views/Shared/_CookieConsentPartial.cshtml
Tailspin.SpaceGame.Web/Views/Shared/_Layout.cshtml
Tailspin.SpaceGame.Web/Views/Shared/_ValidationScriptsPartial.cshtml
Tailspin.SpaceGame.Web/Views/_ViewImports.cshtml
Tailspin.SpaceGame.Web/Views/_ViewStart.cshtml
Tailspin.SpaceGame.Web/appsettings.Development.json
Tailspin.SpaceGame.Web/appsettings.json
Tailspin.SpaceGame.Web/wwwroot/css/site.css
Tailspin.SpaceGame.Web/wwwroot/css/site.css.map
Tailspin.SpaceGame.Web/wwwroot/css/site.min.css
Tailspin.SpaceGame.Web/wwwroot/css/site.scss
Tailspin.SpaceGame.Web/wwwroot/favicon.ico
Tailspin.SpaceGame.Web/wwwroot/images/avatars/default.svg
Tailspin.SpaceGame.Web/wwwroot/images/placeholder.svg
Tailspin.SpaceGame.Web/wwwroot/images/space-background.svg
Tailspin.SpaceGame.Web/wwwroot/images/space-foreground.svg
Tailspin.SpaceGame.Web/wwwroot/images/space-game-placeholder.svg
Tailspin.SpaceGame.Web/wwwroot/images/space-game-title.svg
Tailspin.SpaceGame.Web/wwwroot/js/site.js
Tailspin.SpaceGame.Web/wwwroot/js/site.min.js
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/.bower.json
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/LICENSE
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap-theme.css
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap-theme.css.map
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap-theme.min.css
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap-theme.min.css.map
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap.css
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap.css.map
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap.min.css
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/css/bootstrap.min.css.map
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/fonts/glyphicons-halflings-regular.eot
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/fonts/glyphicons-halflings-regular.svg
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/fonts/glyphicons-halflings-regular.ttf
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/fonts/glyphicons-halflings-regular.woff
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/fonts/glyphicons-halflings-regular.woff2
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/js/bootstrap.js
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/js/bootstrap.min.js
Tailspin.SpaceGame.Web/wwwroot/lib/bootstrap/dist/js/npm.js
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation-unobtrusive/.bower.json
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation-unobtrusive/LICENSE.txt
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.js
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.min.js
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation/.bower.json
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation/LICENSE.md
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-validation/dist/additional-methods.js
Tailspin.SpaceGame.Web/wwwroot/lib/jquery-v
error: The following untracked working tree files would be removed by checkout:
.agent-tools/build-agent.sh
.agent-tools/build-tools.sh
.agent-tools/readme.md
.devcontainer/Dockerfile
.devcontainer/devcontainer.json
.devcontainer/library-scripts/common-debian.sh
.devcontainer/library-scripts/start.sh
SECURITY.md
Please move or remove them before you switch branches.
Aborting