Singer 301a sewing maching

Question

I have a singer 301a sewing machine, I just started learning to sew. I got a bunch of thread behind the shuttle and could not get it out with tweezers. I took the shuttle and bobbin holder out of the machine to remove the thread.Now when I try to sew it draws the thread down into the needle hole? What do I need to do to fix it?Thank YouCarl A. Brady