As mentioned above, the LFPI web page (
https://www.largeformatphotography.info) has enough to keep you busy for days. There's a question and answer forum at
https://www.largeformatphotography.info/forum/index.php that you can browse. You should sign up. After 30 days, you'll be able to see the For Sale section (the delay has kept the spammers away for years).
About every month or two someone posts a "I want to get started in 4x5" or similar thread. The latest one is
https://www.largeformatphotography.info/forum/showthread.php?157682-Interested-in-4-x-5 and you can learn a lot from that. One thing you'll learn is that if you ask 10 large format photographers what's the best (camera/lens/film/developer/etc.), you'll get 11 "definitive" answers.
Bernice Louie posted a reply that is worth reading, in that she suggests starting from the desired end result (likely a print) and working back from that to determine what lens(es) you'll want, and then based on what the kind of photographs you want and the lenses you'll use to get them, what camera to use. So many people start with the camera and then hope they'll figure it all out.
Fortunately, LF is reasonably cheap these days, so you can choose the "wrong" camera to start. If you stick with it, your first LF camera is not likely to be your last. Whether you choose a press style camera, wooden field, metal field, light "field" monorail or studio monorail, all will work fine, you'll just have to decide which works best for you.
I started with a Calumet Wood Field with a Caltar 150/5.6 in college, because that's what they had to use when I took a LF class (in 1988), and the other option was a Calumet monorail that I didn't want to lug around. I got back into LF in 2000 with a 4x5 Tachihara in cherry wood (that someone honestly thought was a video camera once), which I've since replaced in 2008 with an Ebony 45SU, which I intend on keeping as long as I'm still able to take photographs. When people see a wooden camera with bellows, they often assume it must be antique, so I just say "it's an '08" and let them guess the century.
If I had studio space, I'd get a Sinar and a Sinar shutter system, and some day I may.
Lenses? Um, I'm at over a dozen now (65, 80, 90, 90, 125, 135, 165, 180, 190, 200, 210, 250, 250, 300), I can quit any time...honest!
Regarding lenses, assuming you really do want to start with a wide angle lens, wide angle on large format is somewhat challenging, so I'd suggest starting with a moderately wide lens (120, 125 or 135) instead of a 90. 135mm lenses are extremely common and often reasonably priced, 120 (Schneider) and 125 (Fuji) much less so.