What type of c-table or side table would work here (pic)?

I would definitely mount the TV! I would match the side table to the daybed.

You could either use a C table or use a round accent side table---maybe a black metal with open base. If space is a problem, you could place a small accent table in front of the daybed instead of an end/side table, then if you need a light source, mount wall sconces on either side or place a floor lamp next to the daybed. And yes, mount that tv to the wall. Good luck!

Definitely mount the tv. Is the room used more for watching tv and hanging out or as a bedroom? If you use it 90% of the time as a family room, get a coffee table and be comfortable. See if you can find a nesting set or perhaps 2 narrow ones that match/work together which would make moving it for the sleeper sofa easier. It's hard to tell from your pics but is there too much sitting furniture in the room? Perhaps you need a seating/ottoman/coffee table instead of the white couch?

I love your colors but also would like to see a couple of large scale art pieces on the wall.

I would mount the tv on the wall maybe in the corner and try to get a floating shelf table to mount on wall so it gives space to who ever is sitting on the couch.

Beautiful millwork! I would remove TV STAND and mount tv on the wall

Mount the tv and go with a metal side table or something that matches the day bed.

Corner table would work best there to hold the tv measure so it s big enough