Based on the bracket you printed Id say you may be over extruding (blobs everywhere, holes are smaller then expected)
To fix the over extruding I think in Cura you would change the FLOW settings. By default its at 100, maybe bump it down a little.
A good way to test is print a 10x10x5 test cube. Then measure it with a caliper, if it comes out larger lower the flow rate. Bump it down to like 96 and print, measure again.
The stringing can be caused by the temp being to high or the retraction settings need to be adjusted.
Lines on the top layer (Dragging) is usually an indication that the nozzle is too low, try raising just a tad.
Here a good
Troubleshooting Guide that I always turn to if I need help.
And last SPEED. You will eventually find your printers sweet spot, both of mine are usually 50-60 mm/s. For smaller prints I will go lower