I'm sorry to read of your first experience with Windows 11. You may be surprised to learn that this is pretty much the standard setup in Windows 11, Bing search is integrated quite heavily into the OS. You can check if this is actually the case: most of these features can be turned off just by changing settings within Windows, or right clicking the feature, or clicking 3 dots to bring up settings. You don't need to download any untrustworthy software.
Click on the start button to bring up the start menu. Click on the 3 dots. Some of the settings can be changed to turn off search highlights and web content. Now right click the start menu button, click settings. Go to personalisation. From here, you will find lots of settings for the Start Menu, Taskbar and Lock Screen. It sounds like you want to turn off Suggestions in the Start menu, Widgets on the taskbar, and widgets on the Lock Screen. Do have a look through those screens and see if there are any other preferences you'd like to change. There are various settings for Notifications elsewhere in the Settings app, so look for those too. You should be able to reduce the amount of distractions. By now, you should've managed to remove the features that were worrying you purely by changing native Windows settings.
It also sounds like you're currently in Windows 11 S mode. This is a locked down, secure version of Windows 11. You can check if this is the case by searching for ''System' or About' in the Settings app. If this is the case, then I'm pretty confident you've not been infected. One side-effect of S mode is that you cannot change your search engine or browser. You can visit your favourite search engine home page, go to the settings in Edge, and install it as an app. If you really want to leave S mode, then visit the Store app in your start menu, and search for 'Leave S mode' to find out more. If you go ahead with this, you can install any apps you like, even a third party antivirus (you can stick with Windows Security, which is free).
It does concern me that you had a bad experience with HP. If you look carefully at your browsing history in Edge, you may find that it wasn't actually HP, but the result of a sponsored advert and a possible fraud attempt. You should report this to Action Fraud or the equivalent in your country.
If you have a particular feature you need more help with, do post back.