There's nothing you can do for unknown ransomware encryption but wait. If you're lucky, you will get a decryption key in the future but don't get your hopes up
Most decryption key is only released when the culprit is caught
But right now there's nothing you can do but move on from this and learn the lesson of not storing your important data in only 1 place
If you're unwilling to pay for cloud storage, store your important data in multiple storage. At least in 2 places

Run secure erase on your SSD/HDD then do a clean installation of Windows

As mentioned earlier, for unknown ransomware encryption, there's nothing you can do
Not even paid software can help you with this

Pack all the infected files in ZIP/RAR then upload them to cloud storage for backup purposes
After that, secure erase all your SSD & HDD then proceed to install a clean Windows on the PC

Nothing
As I said earlier, if you're lucky, there may be a decryption key in the future. But I can't stress this enough: Don't put your hopes up

Just proceed with my advice and move on. There's nothing you can do about recovering your files for now