Before worrying about timing, he the following.
First, get two pieces of fabric. ..not paper
Check your bobbin, so the thread coming off of the bobbin in the correct direction for your machine.
Next, Chek your threading of top thread. Be sure to do this with the foot up
Check the thread tension according to the normal setting for your machine...
Replace the needle with a new one. A 90/14 topstith works well.
put your fabric pieces under the foot, lower foot, hold on to your needle thread and hand turn for the needle to go down and pull your bobbin thread up to the top and pull to the back.
sew your test. Hopefully everything will be perfect. Best wishes.