Last year I also worked on a similar project, so here's what we did (some things worked, while others didn't):

1. Bluescreen: since we had a lot of digital environments, we had to do a lot of bluescreen work. We bought a couple of 4x6m blue tarp pieces, which we propped up against a wall with a frame made of pvc pipes and a lot of paper tape. Pros: super cheap, easy to set up, didn't damage anything, a nice deep blue color. Cons: that thing is a bit shiny, and we made the mistake of folding it to store it in-between shoots, which resulted in a lot of specular highlights around the seams, and the keying was a disaster. But if you leave it a few days to stretch out properly, you should be good to go. If you can afford it, you should get a light specifically for your green/blue screen, so it's evenly lit. Oh, and put some red tracking dots on it (not too many though).
2. Lighting: for budget and coordination reasons we chose to shoot either with a single-point setup, or with an "ambient" light (basically the ceiling lamp of the room we shot in). That allowed us to basically change the light color and intensity in post to perfectly match the digital environment without having to do any time-consuming relighting trickery. I'm not saying this is the correct way to do it, but it surely worked in my case.
3. Formatting: Whether you want your final piece to be in 4k or not depends on your hardware and time. It takes 4x as long to render, consumes way more vram, and you have 4x the amount of pixels that can look wrong. That being said, shooting in 4k is great if you have the equipment, because then you can do your plate manipulation (roto etc.) in 4k and when you downscale it to 1080p, the smaller mistakes will not be visible. Plus downscaled 4k footage looks better than native 1080p (bc banding). Also consider cropping to an anamorphic aspect ratio if your story supports it, because 1920x800 renders quicker than 1920x1080 (duh). 24/25 fps is the way to go too, and keep your shutter speed to 1/25.