Moist means water when needed, not on a set schedule!
You will find that some plants really suck up the water during certain stages in development. Check your seedlings/plants daily. Personally, I water my seedlings when the soil on top looks dry. I usually don't actually check it - dry soil is a different color from damp. And moist, I'd say, is dryer than damp :)
Firm gently for me means getting good contact between the seed and the moistened soil. I like to use warm water to wet the sterile potting mix, then make a small divot in the top with a pencil or spoon - about
4-5 seed diameters deep, so not really deep. I cover the seed by pushing the seed in and smearing my finger over the hole, which puts some of that moist mix on top of the seed. I usually don't press any harder than that.
With bottom heat provided by a heating pad, you can expect seedlings in 3-7 days.
Don't forget to harden off your plants when movign them from greenhouse to outdoors!