Maybe I'll try decor at first and if I see aggression I'll take them out
Yes, definitely try it. I'm a big believer in enriched environments: plenty of hiding spaces, plants, rocks/driftwood, and sandy substrate. Makes it more secure,enjoying, and entertaining for the fish imo. My del loves to torpedo into the sand and bury herself. My other polys love being under the driftwood. Since I added more plants a few days ago, they have been more active exploring the tank.
If you are wanting to go a more minimalist route: sand, maybe a driftwood piece, a few stones, and a plant or two? Good luck with whatever you decide to add!