Help! I can't get my machine to pick up the bobbin?

you have a few things going on here...1, you need to adjust the tension on the thread. your sewing machine guide usually tells you what tension you need for different fabrics. 2. sounds like you need to oil your machine. there is special oil needed for sewing machines. they sell it at target or any craft store. your manual will tell you where you need to apply the oil as there is usually a particular spot where it needs to be put in the machine. 3. you probably need to replace the needle. If the needle is slightly bent, it won't go into the lower bobbin correctly and pull up the thread. sometimes you can hear it hitting when you go to sew. the jean fabric was probably too heavy for the needle you had and made it bend. You need a heavy weight needle.