Well, normally I get started riding by putting my left foot in the stirrup!
I kid, of course. 45$ is a good price for lessons, and I've never heard of a place that offers lessons to the public and doesn't take beginners. I'd say you probably want to keep in mind what kind of riding you're learning too. If you're a sporty kind of person riding English (the tiny saddle and the classy clothes) can be a lot of fun, but basic equipment like boots and helmets tend to be a hell of a lot more expensive, so that's a cost to figure in. If you're more of an outdoors sort of person you might want to see if anyone is around who will teach you Western (Think John Wayne) it's a lot less proper and a lot cheaper as long as you don't need your own saddle. I didn't see if you said where you live, but western riding may not be an option around you. In any case, 45$ is a solid price for beginners lessons, on the cheap end actually. I think whatever saddle you get in you'll find its a ton of fun, and I hope you'll tell us how it goes!
Oh! One more thing, most riding centers want you to have your own helmet that meets certain safety standards, I got mine for 50$ on Amazon, I'll try to find you a link, because that's definitely an important thing to have.
Edit: here we are: Where I learned and now teach at summer camp, we used these. Cheap and durable.
This is the one I have at college with me. Also durable, but a little pricier and more comfy.