If you do not yet feel comfortable using Linux, then perhaps you better first read the page Working with the Shell and train a bit with the shell/terminal environments, so you can have a better perception of the steps shown in the pages for each version.
You can follow either one of these instructions:
- Follow the official instructions for building from source code: Download v7 | Source Pack
- Or by following the detailed step-by-step instructions provided in the following pages...
Here are the openSUSE versions for which the community has already written step-by-step OpenFOAM 7 installation instructions:
1.1 openSUSE Leap 15.1
Installation instructions for openSUSE Leap 15.1 have been moved to this page: Installation/Linux/OpenFOAM-7/openSUSE/Leap_15.1 - this is an attempt to avoid people getting lost in the multitude of instructions for each OS version.