I am getting artifical rocks and maybe aritificial driftwood(if i can find one)
but should I add plastic plants and other stuff? i read that oscars are smart and get bored if they don't have toys.. And they'll start breaking heaters, filters, etc..
Mine loves to play with things in the tank pull the plants out and swim around with them play with gravel but her favorite is for me to pet her she loves it.
pingpong balls are the greatest thing for them. my oscar would play with his for hours on end. middle of the night i would hear this tapping sound and it was him pushing the ball up to the tank cover. good luck with your O's great fish. wish i had more room so i could have kept mine.