I took a class at my local tech collage and we used paths and singers. There should be a little hook on the case that holds the thread spool. You pull the string through there, then you put the bobbin into place and use the hand wheel to poke the needle down there it should grab and pull the "tail" rite where it belongs in your sight near your foot.
Singer has been making Sewing machines for over 150 years. There have been over 1000 models. Care to mention which Singer bobbin you'd like to thread? Almost every machine is different.