The first pic here is of our new couch we're getting. But, this is just in the store. Please look at the other 2 pics as they show what I'm referencing.

Can you choose a warmer "linen" color for the new couch? That would be best and easiest. Choose paint color last. Put together color palette for house so you have a plan.

Unfortunately; I cannot. I want to figure out a way to
sort of tie the warms and cools together. I see it being done everywhere with the cool tones in metals and combined with warm tones in wood. Also, people seem to be mixing metals more these days and I like the eclectic feel and look. I guess I'm just second guessing everything. Agh!!! It shouldn't be this difficult! 🤣🤣

You should be able to find a rug that works with both the floors and furniture once you've moved in. Don't worry until you have everything in your space. Look for a neutral to warm white for the walls - nothing gray. See if the owners can tell you what color is on the baseboards and doors currently. You could use that same color for the walls or one just slightly more saturated. You'll need to try the samples in your light, up against the floors. Wait on the cabinet color until after you've painted all the walls because right now the red will skew anything you look at. I can see a muted green or taupe on the cabinets with your granite.

I'm planning to paint the baseboards and doors as well. Should I paint them the same color as the walls. That sure would make it easier on me!

You can paint them the same color, but you should use different finishes. The baseboards and doors should be higher sheen than the walls. Most people use semi-gloss die trim and interior doors.

Benjamin Moore White Dove is an excellent and very popular white. It’s a good color to sample. However, I would wait to choose a color until you can look at some large samples in the house.

Are the floors dyed greenish concrete with a shiny finish?

What are those floors? IMO that wouldbe where I would be spending money to change those to something that does not dictate every other choice in the house . As for wall collr you need to be in there with your stuff and proper lighting before any wall colr can be chosen . To start that kitchen lighting is close to useless . IMO wall color is long way down the road so wait .

Pretty sure the floors are a penetrating acid wash stain…meaning the only way to change them is to cover them up… if you are keeping the floor as is….…i think you are on the right track with the plan to paint the walls white….i would even do the cabinets a white to match…if you are set on the couch shown …i would do all the trims in the couch color..creating a monochromatic beiges and white overall look…..then you can add accents …like art …an accent chair…picture frames …throw pillows …etc…..that match the floor color….keeping that powerful color to a minimum …

With concrete floors …thick shag area rugs are a perfect contrast to the hard surface floors and add a lush feel to the the room…

We had the same floors in our summer home….Absolutely loved them in green

I don't think your sofa choice is large enough of a statement to dictate the wall color in your room. Will you be adding a rug? You may want to wait and take a color out of it. The kitchen color is more a concern. There's a lot going on there. Are the cabinets a yellow? It's a color mess IMHO. I would not paint doors/trim same as the wall. The walls will no doubt be changed over time. The cupboards/doors/trim will be more stationary and should be thought of more like a frame to the rooms, while you embellish inside them.