How to stop erosion, with a house on sandy hill?

https://comfortablydomestic.com/2013/06/reclamation-7-erosion-control-project/

These people did a really involved but successful project - highly recommend going through these blog posts!

erosion is either from water or wind. wind breaks help. shrubs, evergreens & trees. water....well where does it run to and can you gravel that area?

Water - do a french drain

Wind - do a windbreak fence

Slope - do a retaining wall (s)

Slope - ground cover with good root system (something you don't water)

Get a soil engineer if its threatening your house to make a plan

Terracing

I agree with the terracing, start with that and you can do a multitude of things with the area. If you do smaller terracing you can decorate each area differently for entertaining, shrubs, flowers, etc.