First terrarium initial watering help

So I started my first terrarium and have everything minus my plants completed (waiting for them to arrive in the mail) My question is how do I know it’s sufficiently watered after set up?

Before I put the moss in I sprayed the top of the substrate down and a couple drops did make it down to the drainage layer. Then after I put the moss in I sprayed the moss down as well. After a few hours, the soil is back to being basically completely dry and all the sides of the terrarium are foggy.

Should I spray it down from the top again tomorrow? And/or should I use a dropper and squeeze water down the sides of the glass tomorrow? Not sure how my new plants will do with dry soil.

Thanks for your wisdom!