I would agree with much of what others have posted here with one exception. Several folk have recommended a roll film holder for the 4x5 - and I would not get one of those as you are starting out. Like you, I moved from 35mm to LF, and one of the biggest changes between the formats is getting into the mindset of really contemplating each image and analyzing it before releasing the shutter. A roll film back encourages your 35mm brain to function when you have the LF camera in front of you. It is much better to immerse yourself in the LF world and get in the habit of thinking in that mode before trying to treat the LF camera like a big 35mm.

Personal preference: I shoot 99% of my images in B&W. Ilford HP5+ is a good film with lots of exposure latitude, so it is hard to get a negative that you can't print with HP5+.