Having just started myself, I don't have much advice for you but can say that we are still in the very early stages. So you definitely haven't missed the boat.
I have actually been thinking of building a 6-8 GPU mining rig but with the inflated pricing right now that is a very expensive endeavour. Might hold out and wait for the prices to come down once more cards hit the market.
RE: Mining cryptocurrency? Am I late for the game.