I’ve updated unity now here showing nothing to select or create projects. I opened a scene from folder then it opens but if i go to make new project shows this blank screen. 
There are many questions about buggy behaviour in the editor after updating to 5.3, I’ve had some problems too.
My best advice so far is to uninstall this version and download and install 5.2.0f3, which seems to be the most stable in the 5.* series.