You have a brand new laptop which means it has a warranty. You need to use your warranty! If you install Win 7 you will completely void that warranty. If you tinker around with your system you could void the warranty as well if you inadvertently do something you shouldn't. All of their contact links are on their website.
As for downloading Win10, I think you mean download and install, but if you can't use your browser, then you can't get to the Microsoft website to get to the Win 10 anyway.
If you completely shut down your laptop, leave it powered off for several minutes, then turn it back on, does it still not work? I ask because Win 10 has a reset feature built into it for when Win 10 becomes corrupt (as yours has done). Start > settings > Update & Security > Recovery > Reset. This will completely reinstall Win 10 for you. You will have an option of saving your files or letting it overwrite everything.
I recommend you call HP and handle this via your warranty. But if you insist on trying to resolve it yourself, then try shutting down/restarting/ then using the reset feature. If you still can't get to the reset feature, and don't want to call HP, then here is the Microsoft link to download, then install, the media creation tool for Win 10. https://www.microsoft.com/en-us/software...