Welcome...Are you feeding them laying feed? I mixed my growing feed with laying feed for one week...then gave only laying feed and within two days my RIR's were laying. They were 20 weeks when they started laying. Now all but one girl is laying. I have 2 EE, 2 Buff Orphingtons and 2 RIR. I also left golf balls in a couple of nesting boxes at 19 weeks. They had no problem knowing where to lay. They do free range but mainly later in the day when I am home and out working in the yard. They tend to lay in the morning. If you end up keeping them in the coop/run area do it early in the day and see if they will lay in the coop. If you don't have a nesting box, make a quick one out of a couple of big shoe boxes or plastic tubs big enough for them to fit in. Of course fill with straw or shavings.
Good luck.. It's exciting getting your first egg.