bootstrap

[bright barn]

I would read the error message.
Also, if your app was working before, you installed and uninstalled all these packages, can't you just revert to the previous version using git?

That's basically one of the points of using a version control system, yes. Having versions, and being able to switch back to a previous version.
Regarding "idk how", what do you mean? You don't know how to read the error message?

Are you using git? Do you regularly commit your changes? Did you do it before those npm install and uninstall?

If not, have you read the error message? What does it say?

Well, that's one more thing you really need to learn for the future, to avoid such awkward situations. Did you read the error message?

Oh my. NgModule's bootstrap property has nothing to do with the CSS framework named Bootstrap. You basically removed code that is needed by Angular just because it contains a property named bootstrap.

Re-add the boostrap property that you removed from the NgModule.

You probably have a file named app.module.ts. It contains the root module of the application. It's a class decorated with @NgModule. the object passed to this decorator is supposed t have a property named bootstrap: bootstrap: [AppComponent].
I really really wonder how you're learning Angular. Do you just try random things, or do you read a tutorial or a book? Because the second way is way more efficient.

I don't see anything missing, no.

Hey, would you happen to be a surgeon? How can I have a good surgery operation. Need it for tomorrow. 🙂
Don't try to make something beautiful. It's probably off-topic anyway. Instead, do something correct.