[completely fucking out of my element] help me pick a cut and seasonings to make a steak burrito for my gf

I've been a pescatarian for like, 6 years, and I'm not gonna get into all that, because I don't care and neither do you, it is what it is. The point is... I have no idea how to cook a steak, season it, pick a good cut, or anything.We're getting together to make burritos at my place, and I said I'd buy ground beef for her but that I didn't know how to make it [because I have no fucking idea. I know fish and vegetables like a motherfucker, I'll make some mean fuckin' rice and beans but meat I'm lost in the sauce] but I decided steak burrito is way better than ground beef burrito, and literally nothing in the world is too good for her.Anyway, please help me I have no idea what I'm doing and she's super important to me and I want her to have an incredible burrito to hopefully create memories that last for the rest of our lives, fingers crossed.I'll delete this if this isn't the right place to go, but I mean it is called r/steak via /r/steak http://bit.ly/2VjMKYX