You don’t need to wear a tuxedo shirt to the funeral, but its great if you do. If you don’t plan to put on your Sunday best or don’t have them to put on, still go to the funeral to pay your respects. Just try to dig out the blue jeans you have with the least holes in them and the ones that are least faded. The nicest shirt you have in the closet will work with the jeans and any footwear is fine. It is best to go to the actual funeral in dress clothes, but no one should ever be prevented from attending, because they didn’t throw on a pair of slacks with a dress shirt. I hope this helps when you have to go to the funeral home for visitation or to your next funeral.