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!