How often do you take a rest day?

I take a day off during the week in between my workouts usually Wednesday and take weekends off too..so 3 days . On my rest days I try to still get in my steps though

I think you'll get vastly different answers here for this and it all depends on what activity you are doing and how often...and how long your personal body takes to recover. You said you're running and I'm a runner too so this is what I do.

But, IMO --- having at least one day a week where you do no intentional exercise is good and can't ever hurt anything. I personally run ~10k 3-4x per week(working on upping that mileage)...so I tend to have two days of no running between my runs (but plenty of people run everyday...even longer distances and are fine). I typically will hike or walk on those days --- I will definitely hike or walk on at least ONE of those days and maybe on the 2nd but also maybe just do nothing. If you have a hard run, walking the next day is what you SHOULD do...don't use that next day as the 'rest day'. It's better to get some recovery in your muscles by using them. It will take longer if you stay off your feet.

I am only doing walking for cardio so I am not doing rest days at the moment. I might try to get into running and some upper body lifting, and when I do that I may incorporate a rest day.

I don’t take many days off, but I do vastly vary the intensity. For example, I cycle 3 days a week, run/swim 2 and usually do some hiking or surfing on the 7th, plus tennis 2x a week.
Some of those runs are really short and slow. Some of the swims are just paddling around and playing in the waves. But I make a point to get in some activity just about every day.
If I’m feeling pain or life gets in the way excluded.

I take 1-2 rest days per week, depending on my needs.