Make sure the bobbin is turned in the right direction and also make sure the needle is inserted correctly into the needle holder, then see if it will pick up the thread and if not your machine could have a timing problem

First thing to do is fit a BRAND NEW needle - ensure it is the correct type AND that it has been fitted facing the correct direction (it could be bent ever so slightly .... not detectable to your eye) Next recheck thread path - use a QUALITY thread (not a cheapie). Esure that the bobbin has been wound on tightly (should not feel spongy when pressed with your nail) and that the bobbin has been inserted correctly into the bobbin case (can go two ways, but the thread will not be feeding correctly unless the bobbin is in the correct way. Still not picking up? .... remove the shuttle hook from the machine and check VERY carefully for ANY slight burring on the hook point, or anywhere along the edges of the hook behind the point. If there are any, they will need to be carefully removed using 400 or finer wet and dry abrasive. None of these solve the issue, then it most likely is timing or the clearance between the needle scarf and the hook - both best done by a technician as part of a routine service :)