"I was told I should take Vitamin D. I can only find D3. Will I get what I need by taking D3 or should I make sure to find vitamin D?"
Yes there is.
Yes there is. We need Vitamin D and D3 is a fine source but, the Vitamin D pathway is somewhat complex. It is possible to take to much Vitamin D and there are toxic effects that can occur over time.
Take a look at this article and I recommend you do some more reading about it.