GodHand MIGAKI-Kamiyasu-Sanding Stick 10mm-Assortment (#2000, #4000, #6000, #8000, #10000) GH-KS10-KB for Plastic Models

https://www.amazon.com/dp/B0F2DL1JJW?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1 so i bought this sandpaper from amazon thats 800 grit which is not what i was expecting it was much rougher maybe like a 200 grit. and i was wondering if i am the dummy here? also if i am the dummy where can i find a bunch of 800 grit godhand and 8000 grit, do i need alot of it or just this one pack that i found on amazon? https://www.amazon.com/dp/B07YG9XRSH?ref=ppx_yo2ov_dt_b_fed_asin_title