I want to buy a video card for my System Unit, so that i can Render more in my Video Editing, and also play Games, but what Video Card should i buy??
Knowing what video editing software and related 3rd party plugins is key to being able to answer your question. I would ask your question in a forum dedicated to the video software you are going to run. It is likely your machine won't be too picky about being able to use any card you pair with it. In general, for video editing purposes, your CPU is not very powerful, regardless of GPU you pair with it. If all you're doing is an occasional home birthday party video at 1080p and not professional editing work, it may be just fine for you. Again it goes back to the requirements for the software you are going to run and YOUR expectations.
Depending on the level of your video editing requirements and also the application you will be using, I recommend to use a Radeon Pro WX graphics card. You should be fine with your current CPU