Fill the bobbin
Insert thread into the spool pin: Place the spool of thread on the spool pin and cap it with a spool holder if your machine has one. In most cases, the spool should be placed in such a way that the thread exits from it counterclockwise.
Pass the thread around the tensioning disc: Pull out the thread from the spool and wind it around the bobbin winding tensioning disc, which is usually on the opposite side of the spool pin, above the needle.
Thread the bobbin: Insert the thread through one of the holes in the bobbin the wrap it around a few times to secure it in position, then put it in the bobbin pin. Slide this pin over to the right so as to lock it in place then begin winding by pressing the foot pedal.
Once full, the machine should stop automatically. Remove the bobbin and cut the thread, leaving a tail of about 3 inches from the bobbin.
It might be helpful:
Thread the upper half
Through the upper guide: With the thread spool still in the spool pin, pull the end of the thread and wrap it around the upper thread guide from back to front.
Through the U shape: From the upper guide, pull the thread down using the imprinted directional arrows as a guide. Loop it on the lower tensioning discs then back up again. After doing this, the thread will create a narrow U shape, which forms the title of this part.
Around the Take-Up Lever: After the U shape, the next point is the take-up lever, in which you should wind the thread through its eye, then bring the thread down to the needle area.
Thread the needle: The final step is to thread the needle. Most modern machines come with an automatic needle threader that simplifies this task and once done, proceed to thread the lower section.
It might be helpful:
Thread the lower half
Insert the bobbin: Identify where the bobbin should be inserted, which is either directly below the needle or at the side. Find this compartment and open the case to expose the bobbin slot.
Unwind a few inches of the bobbin thread then insert it into the slot depending on the direction that the thread should be exiting the bobbin. Insert the thread that you wound out into the required notches, then close the compartment.
Expose the bobbin thread: In this final step, simply turn the handwheel to raise and lower the needle, and it should pull up the bobbin thread. Once this is done, you can begin sewing.