To directly address the two questions:
Are there some partitions I should keep?
There's nothing you must keep, but having said that keeping certain partitions may have an effect on the overall experience. See #2 and #3 for some thoughts on what can be kept and the results of doing so.
If no, will I be able to revert back to Windows and possibly reactivate my copy if I change my mind in the future?
If you do remove the Windows boot partition, options #1 and #2 provide routes to reinstall if needed. As far as activation, as others have noted all modern laptops have the license baked into them, presumably in the BIOS somewhere, so all you need to do is install Windows and it'll just work.
That said, in my humble opinion, there is no best single solution. I can see several possible courses of action, each one has various benefits and liabilities.
- Completely remove everything, format the entire SSD, and install Linux. Benefits: maximunm space for Linux and no need to deal with dual boot configurations. Liabilities: the only way to put Windows back on would be to create installation media (i.e. flash drive) using the media creation tool, and do a full reinstall of Windows. I don't personally think that's a major issue, and has the hidden benefit that it removes all the vendor bloatware that one typically finds on a new Windows machine. Your actual mileage will vary. Important note! The media creation tool is a Windows executable, so you'd be well advised to do this before deleting partitions.
- If the OEM placed a full recovery partition on the SSD, leave that in place, and install Linux in whatever else is left over. Same Benefits as #1, and also restoring Windows is significantly easier, albeit you typically get the bloatware. Recovery partitions are usually 10 to 20 Gb in size, often seen as the last partition on the SSD. Beware that different vendors may have different ways to access it, so it's probably a good idea to learn how to use it before pulling the trigger and installing Linux.
- Shrink the Windows partition, and Install Linux in the space created. Benefits: You have access to both systems using a dual boot tool. Liability: less space for Linux, depending on how large you keep the Windows Partition. Although that's likely to be less of an issue since Linux runs very comfortably in a small fraction the space required by Windows.
