İs it okey to use free assets if i am gonna sell my on asset store ? İn the end ı won not sell model, ı will sell a game which is different category.
No, unless you have written permission from the asset creator/copyright holder. Many free assets created by Unity Technologies may be included in assets (check the license), but for all other assets contact the asset creator.
If you want to sell an actual game, then the Asset Store is not the place for it.