Well, I have to say this first:
Before getting into believing gear is what makes a great photo, study great photography.
Shoot with what you have and know its limitations. If you don’t understand the limitations of the gear you have, you’ll never know what you’ll need and how you can use it.
I know my gear inside and out and know the first time I look at a situation, what camera, lens, and settings I’m gonna use because I have found every usable and unusable boundary of each piece of gear.

But if you are looking for a good-ole trusty lens, the 50/1.8 is a great lens.
It’s good in low light situations and will give you nice Bokeh when you want it. It’s a little slow to focus sometimes, but when it’s in focus, it has a nice lock to it so you know that the focus is on.
50mm is around what our eye sees and its a great lens to learn on.
After you shoot with it a while, you’ll know what focal length you’ll want to go next.
(i.e. After I had the 50/1.8 for a while, I needed something to get closer in to the action of the ceremony without moving around, so I bought the 70-200/2.8. I also knew I wanted something wider for shooting tight spaces in getting-ready rooms and receptions, so I went with the 14-24/2.8 and 24/1.4 soon after.)

Hope this is helpful! :)