Is there any way where i could use C++ directly with plugins…
Are there any tutorials that teach me how to create plugins for unity 3d using c++
Yes, you can use plugins, as you said, but they are a prerogative of Unity Pro and mobile. So, if you are using Unity free for making a PC standalone, you cannot use them. You cannot use them even with the WebPlayer because, for security reasons, they are deactivated in that kind of build.
The link that I have provided is from the official documentation, and you should not have problems in uderstanding it. By the way, I think that it would not be so easy to find other, unofficial tutorials, since it’s not a massively used feature.