I have an Edison clone. When I got it the case was filled with bent and broken needles. I was not as knowledgeable when I got it as I am now and had fits with it. The needle bar height was off, the presser foot height was off, and in trying to get that right I made matters worse.
It took me two years to learn enough to get it fixed.
I'd start with a thorough cleaning, but don't touch any adjustments. Then make sure the needle is in correctly, Flat to the Right and threaded Left to Right. Then try again.
Also when threading the bobbin case make sure the bobbin turns the correct direction when you pull on the thread. It should turn clockwise.
Joe