Sourdough starter used too early
Using a starter with insufficient activity is basically the same thing as forgetting to add yeast to a non-sourdough loaf. If there's very little activity in the starter, then you don't have an established colony of wild yeast so there's nothing there that will make the dough rise. At this point, your bread is pretty much a loss. You could try to turn it into some form of flatbread by frying small rounds of it in a pan if you don't want to throw it out, but you're not getting a loaf of bread out of it.
As for your starter, the brown liquid is most likely hooch. It typically indicates that you're not feeding your starter often enough. Typically, your starter should be ready for use in 7-10 days from starting it. However, lots of factors like the temperature in your kitchen and precisely what kind of flour you use can affect the time it takes for a yeast colony to establish itself. Using it before you have a stable colony of wild yeast is a waste of time and ingredients since without the yeast it cannot replace commercial yeast in your bread. Patience will get you there faster than rushing.