I agree with Common Yellowthroat -- a Yellow Warbler would have bright yellow in the tail feathers, while any of our orioles should show wing bars and either yellow undertail coverts or some sort of face pattern (or both).
I have VERY limited experience with shorebirds. Both pictures in the last few days in Saint Joseph, MI, Southeast corner of Lake Michigan.
1. Low light in the evening. Guessing Sanderling because of lack of hind toe? But the beak doesn't seem right? I don't know...might be normal.
2. Semipalmated Sandpiper because of partially-webbed toes?
No, it's not a Stilt Sandpiper. They're scaly-looking as juveniles, with dark centered scapulars and tertials that have pale edges. The tiger-striped scapulars and tertials you see here are a classic ID point for juvenile Short-billed Dowitchers.