Installing on virtual box requires a little but more configuration on your end. Also, there is an ISO specifically for making a VM machine of Kali. Are you using that one? When you are installing you are mentioning that you are running into issues.. Can you tell us what the issues are, and any what specifically are the errors?
Remember Kali is really not made for the beginner level, so keep in mind that it will be difficult like this for many things to come. Might I recommend trying to familiarize your self with another Debian based Linux like Ubuntu or some other user friendly OS, so that you get a ground working knowledge of how the internals work.
Fact, Science and the Pursuit of Knowledge. Working to secure your networks from threats; Outside and Within.