Does chessbase have the biggest collection in the world?
Who knows? Why are you so hung up on quantity instead of quality? You have heard about DBs with duplicate games, typos, GM Draws and other deficiencies right? Do you really think the BIGGEST DB in the universe is going to be immensely more helpful to you than any other DB?
Also I just noticed you're not too familar with PCs but you're all set to use massive DBs on PCs? I think not but what do I know? I've only been using PCs since the 1980s...
lol
You might take a look at ChessOps. It covers, to me, just about every opening there is with variations. And it explains each move, step by step. Very helpful to know the Openings by name and each move. Very easy to navigate the program. Try it. You may find it very helpful.