All the product item pages and the cart are resolving to a 404 page in my shop page

My store is not working, but it worked after applying some changes 2 days ago. All product pages are going to a 404 page.
I set the Store Base page to ***Shop, and since then, the store is not working. Last night, it started working after clearing cache and resetting Permalinks, but today I realized the cart was going to 404 page. And after fixing that now are the items that are not working and going to 404 pages.