It always start with one gpu and ends with crazy farms. Goodluck with your first step , i am mining for 2 years now and still alot to learn , by the way i started with one GPU also 
I'm already planning my next gpu purchase. When this price dies down I'll grab some. I still have a ton of stuff to learn but my understanding of crypto and the mining process has increased substantially since I started mining. Good luck to you as well!