Yes both look to be sandstone but the 2nd one is water worn smooth. I wish I could tell you they were artifacts but I cant, sorry. The best thing you can do is take those and set them aside till you get to looking for about a year or 2 then go back and have another look at them. After you get better at finding the keepers you will then know the difference between the rocks and artifacts and know why those were never used and are natural. Keep looking, rock