Split Intro Page for two different sites

I would like to make a second wordpress blog, next to the already existing one.

At first there has to be a split intro page (with ‘click here for blog 1’ and ‘click here for blog 2’). And after this the two different blogs. I prefer a different login for both blogs.

If this is possible, what is the way to do it? And how do I link it with the intro page? Thanks!