Help! How do I install drainage in my seating area.

We recently re-did our backyard in a new build away from turf and random plants.

I'm not a landscaper and know there's a lot of things to think about in terms of aspects and slopes to ensure proper drainage. They had some the slope properly and we tried to keep it the same but we did put in a seating area which with frantic sand, compacted with a plate compacter.

As much as I tried, it's still sloping toward the house and I don't want the foundation to keep getting wet (built on a concrete slab).

Any ideas of how to install drainage in this area? There is a box drain about 4m to the left but I think it is reinforced with concrete and I'm not sure how to go about connecting pipes anyway. Pretty sure there is an agi Pipe installed in the backyard already but the water doesn't seem to be able to seep through the compact sand.

Pics for reference.