1) I have heard very mixed reports about the Modern Mystery School; your mileage may vary, but it's not something I'd recommend.
2) The occult scene these days is a very, very mixed bag. Most of the worthwhile schools keep a low profile for a variety of good reasons, and nearly all of them want to see some evidence that you're serious about being interested in magic, because very few of the people who sign up for any course of magical training are actually willing to put in the work. On average, 90% of the people who sign up for a training course in magic drop out without ever completing a single exercise; this is something I've heard from dozens of teachers, and I've also found it to be true myself.
This is why I recommend that you choose a book that provides a good course of basic magical training, and follow that course exactly as written -- without leaving anything out or making any modifications -- until you've finished it. This will give you a good solid background in the basics of magic. It will also be something you can mention to a serious occult school, which will make the interviewers go, "Okay, this one's actually serious about it."
Re: advice for the unexperienced
2) The occult scene these days is a very, very mixed bag. Most of the worthwhile schools keep a low profile for a variety of good reasons, and nearly all of them want to see some evidence that you're serious about being interested in magic, because very few of the people who sign up for any course of magical training are actually willing to put in the work. On average, 90% of the people who sign up for a training course in magic drop out without ever completing a single exercise; this is something I've heard from dozens of teachers, and I've also found it to be true myself.
This is why I recommend that you choose a book that provides a good course of basic magical training, and follow that course exactly as written -- without leaving anything out or making any modifications -- until you've finished it. This will give you a good solid background in the basics of magic. It will also be something you can mention to a serious occult school, which will make the interviewers go, "Okay, this one's actually serious about it."