pls can someone recommend an AE version

Just install the earliest version available to you from the CC Installer/Manager, and see if that helps.  

What issues are you having?  It's important to note that 8GB of RAM is absolutely minimal for AE, you should really have at least 16GB.

Otherwise, managing your projects and expectations is important.   Don't work in too high a resolution (1920x1080 on your machine would be the maximum I'd work at).  Keep previews at 25% or 50% resolution while working.  Avoid using source files that have very high resolution, including still images.  Limit the number of effects you're applying when possible.  Don't expect previews of more than a few seconds long - render test files instead.