Repeat to your self; "Do not spend any money on RR stuff for at least 6 months". If you do not listen to your self please listen to me. You will regret most everything purchased at the outset of being new into model trains.
Visit lots of model RRs, all scales. Ask advice of those who have actually built something. Many forums feature phantom experts. My favorite signature: "I'm not an expert, I just play one on the forum".