Last year I was in more or less a similar situation as yours. In my case, I have already shoot plates, but always with classic gear: mostly 6.5x9 with a Patent Etui / Tessar 12cm, and 9x12 with a Voigtlaender Avus / Skopar 13,5cm. These sizes are easy to find here in Europe, and since I do mostly B&W I do not care of color emulsions for these sizes (although I still have several boxes of both negative and positive at the freezer). I enjoy shooting 6.5x9 on my Plaubel Makina IIIR, but usually I load it with any of the rollfilm backs.

Last year I decided that I wanted to dig my toe a bit more seriously into LF. In my case, I hunted down a Linhof Super Technika V with a Schneider-Kreuznach 150mm lens. I like Wide Angles best, and therefore I settled for a Technika V. A Technika IV may have been a good alternative too (MkV) but I found my V at a very good price. As you know I am sending it to Münich for a CLA, but even with this expense on top of my purchase price, it is still a good price. With patience, one can find bargains. The Tech V also has rear movements, something that I very much wanted.

Graflex are also a good way to start, much cheaper than Linhof. In my case, I went for it knowing what to expect of LF and with a bit of background, if only with limited movements from my classics.

Your questions are easy to answer: as soon as you pick up with your readings, you will discover the basis and understood the idea behind LF. I'd say that you should either a) go cheap for now while you decideif it suits you, with something preferably holding its value in the meantime; or b) read and learn what you need for what you want to do, and buy accordingly :-)