So, to make a black and tan, you don't actually need a creamer faucet or a nitro setup, but it does make for a more authentic experience.
To run nitro, you need a separate regulator, gas tank (beergas or straight N2), AND a stout faucet. However, you should still be able to make a black and tan with any two beers of significantly different finishing gravities, no separate gas or faucet required. Do a quick google for "black and tan spoon trick."
Many beers (particularly stouts and english beers) are better on nitro, though, and once you put together the scratch, it may be a good investment if that's something you love. I cut my beer teeth on Bass/Guinness B/Ts, but there is no way to serve a dry Irish stout in my opinion, unless you have a nitro tap with a stout faucet.