I've tried everything I can think of, watching countless tutorials, manually downloading the dll's, ...
If you have manually downloaded dlls from a questionable source on the internet you may have created the problem.
It's also possible that your software needs a 64-bit version of msvcp120.dll and you installed a 32-bit version. Or vice versa. Or put them in the wrong location.
msvcp120.dll is a VC++ runtime file that should ordinarily be installed by using the Microsoft redistributables available from https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170#visual-studio-2013-vc-120--no-longer-supported. Both 32-bit and 64-bit versions are available.
Have you tried uninstalling/removing anything that you previously installed and running a complete malware/virus scan?
Do you have any backups of your system that you can restore to a state prior to any changes that you made? Or an available system restore point?
In any event, if you cannot resolve the problem yourself you will likely need professional assistance.