Here at chess.com you could get free databases; I think here: http://www.chess.com/downloads/database+programs/?sortby=download_count&cat_id=2&keyword=
EDIT: Databases show you what GMs would play in the beginning, people are quite positive about SCID3.6.1.
It certainly isn´t wrong to play 1.d4, after you can always play 2.c4
There are though a lot of openings to keep you busy with...
I am planning on building an opening repertoire as White, I really wanted to play 1.d4!
But how do I keep up with so many Black responses?
What sort of computer program is suited for this?