No vaadin output on simple project, need help

Hi, I’m really new to spring boot and all the ecosystem and programming overall.
I’ve started a little project to learn vaadin and spring boot, but I can’t even get vaadin to work with a little “hello world” example.
I imported the dependency into the pom.xml via Vscode maven plugin

    <groupId>com.vaadin</groupId>
    <artifactId>vaadin</artifactId>
    <version>24.1.3</version>
</dependency>```
And my Mainview looks like this:
```package com.example.demo;

import com.vaadin.flow.component.html.H1;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.router.Route;

@Route("")
public class MainView extends VerticalLayout {
    
    public MainView() {
        add(new H1("Hello, world!"));
    }
}```
I have some other repositories and controller running (getmapping and postmapping) which are connecting to a mysql database.
Are these maybe interfering each other?
Because I get some data over those routings, but via @Route("") I get the Whitelabel Error Page.
Thanks for any help.

Long story short: the best starting point to create a new Vaadin application is from start.vaadin.com especially if you don’t know spring and/or vaadin weil.