Many users are unaware of the fact that the Linux kernel developed by the Linus Torvalds team contains proprietary software to make it, for example, more compatible and universal with certain hardware.
So if we'd like to use GNU/Linux in a 100% free way , discarding these non-free added components, we should use some of the recommended distros by the Free Software Foundation (FSF) that you can find in this link.
Another option is to install a Linux kernel with the proprietary software already removed and that, therefore, can be installed on any Linux distribution. One of thsese options is Linux free, a project of LATAM FSF.
If you'd like to try it, you can read this article to learn how to install and use it on OpenSUSE.