How active am I

I'm a care assistant as well. I put lightly active because the majority of the time I'm not on my feet and when I am I'm going at the pace of someone who is trying to recover (walking alongside patients). Though there are times when the work is physically strenuous (boosting, lifting, turns, and transfers) it for briefs stints of time. I totally get the struggle to get in those workouts WITHOUT giving up sleep. I try to include my kids in my workouts. I go to parks that have tracks around them. They walk with me and then I stretch while they play. It's a great way to have quality time.

You can do it any way you prefer - you can put in sedentary and log your activity or you can put in lightly active and not add in activity, it works the same...
When just starting out I'd advise sedentary. If you use an app to count your steps that would let you see how active you really are.
ie up to 5000 steps is sedentary, up to 10000 steps is lightly active etc

It's not a question whose answer you really have to get right. If you choose something more active, the program will assume you can afford a few more calories, even before you start logging deliberate exercise routines. If you're not really that active, you'll find that your loss rate is a little less than you might have expected otherwise, and you'll either have to reduce your eaten calories or increase your exercise calories (bearing in mind that your exercise calories are almost certainly going to be over-estimated, so a good rule of thumb is to cut them in half when you're making calculations and deciding what to do). The program is just trying to figure in some base level of ordinary activity before you start logging your special workout activity, so you don't have to keep track of every step you take all day, which would be more trouble than it's worth for the kind of thing you do day in and day out.