I tried to create a barn cutter and what would think would have sharp lines the Ender 3 Pro went in circles to which after a few rounds then finally started it sharp edges but because of the stringy mess it did before my would be cutter wont stick to the bed cause its laying on a pile of strings.
A picture would be helpful but it sounds like your nozzle is too far from the bed. Your first layer should be close enough to the bed that the layer lines just touch each other and slightly squish into the bed. If it is putting down strings it is too far.