you should try to complete a doodle before posting it because there is little or nothing we can really tell from this example.
your line quality is okayish, but can be controlled and improved upon alot, and the toning needs more exaggeration because this 3d object (?) looks really flat.
try copying a pretty basic drawing which you like the look of, this will help you learn about proportion and most probably line quality, because doodles are fun to do and do help you practise, but, imo beginners will get better by following other artist's examples before going in their own direction.