Sedentary?

ShyGirl1978sm

I'm hoping this is the correct place to ask this question! I'm still finding my way about, lol!

I work an office job and don't, sorry DIDN'T!, take any regular exercise but I do walk a lot as I don't have a car. I'm aiming to do 10k steps a day, and I've found with taking the long way to work and going for a walk on my lunch break that I'm doing approx 8-9k steps a day (this is only counting the steps I walk outside, and I'm hoping to be at 10k in the next few days). Should my activity level still be sedentary?

I also plan to start doing 20 mins aerobic exercise 3 times a week in the next week or two (I'm trying to be sensible rather than all gung-ho as I've done that in the past and I end up giving in quickly). Would that be when I changed my activity level?

Thanks, any and all advice welcome!