Here's a good step-by-step Wiki on adjusting tension.
https://www.wikihow.com/Adjust-the-T...Sewing-Machine
Your tension is definitely off. Follow all the steps shown with the top part of your machine before you try to adjust the bobbin casing screw. Sometimes it is easier just to buy a new unit than adjust that casing...
Clean everything inside the bobbin casing. Try putting in the bobbin so the thread comes off the front and from the back, see if anything is different. Make sure your bobbin (and top!) threads are coming off the back you as you sew. Notice in the videos how they pull the treads to get started. Your problem, however, is greater than that!
Some machines are picky on whether their foot is up or down when you make adjustments, likewise, some like to have the needle at the High position (there is usually a mark on the wheel/case for this, maybe subtle or use a screw or something but it is usually there). You can try making an adjustment and see whether anything seems to change, then try the reverse (so if you were doing it foot down, try foot up).