The best thing to do is ask a lot of questions and do your own research using the internet as a source for good. Look up terms on reputable websites like Mayo, Memorial Sloan Kettering, MD Anderson, etc. Some of them, like Mayo, explain things in clear terms. The days between diagnosis and treatment plan are the toughest but doing that research not only serves as a distraction it helps make you an informed patient and gives you the basis for asking informed questions of your medical team.
We've all been there and we're here to help you through it!