When it comes to your actual race, it's not a good idea to run in old running shoes or brand new ones. You should wear shoes that have about 40 to 50 miles on them, so they still have most of their cushioning left. So, you can buy a new pair of running shoes about three weeks before your race and do several short runs and one longer run in them. If you've been happy with the running shoes you've worn during training, get another pair of the same ones for your marathon. There's no reason to change anything or try something new when you're so close to your race day.
Wearing your marathon running shoes the day before your marathon means that they won't have time to decompress before your race. Try to wear a different pair of running shoes or very comfortable shoes when walking around the day before your marathon.
