if i made some fresh bread from scratch, how long is it supposed to last...?
Depends.
There are so many factors that come into play: the humidity in your kitchen; type of bread; where you slice it; what you store it in.
When I lived in VA, I could not keep a loaf of sourdough bread more than 2 days in the humid summers. In dry Northern California, that same bread will keep up to 4 days.
A baguette is not worth eating after a few hours. But if you reheat it in the oven, you can bring back the nice crust.
This will explain a few things about storing bread
Plastic or foil? Room temperature or fridge? What's the best way to keep your homemade yeast loaves and rolls fresh and soft (or crunchy and crispy)? Find out here.
www.kingarthurbaking.com
Starch retrogradation is the cause of the stalling of bread.