It skip stitches,and part time want pick up thread at all.

Also be sure you're using the right type of needle for sewing with knits you need a ballpoint, sewing woven fabrics you need a sharp. Happy sewing good luck and God bless Angela

The issue could be that the needle is not fully inserted. This will cause a difference in the timing of the thread going around the race which holds the bobbin.

Other causes could be wrong size needle. Needle put in the wrong way (i.e back the front). blunt or bent needle. Skipped stitches- use new needle. Make sure it is the right size for the type of material you are sewing i.e denim use size 14-16, poplin/calico size 12, silk/chiffon size 10. Also check that your thread is good quality. Is it poor quality cotton that breaks easily when to pull it?

Do you have the bobbin in the correct way?

Check the book to see if you have threaded the top thread correctly, especially make sure that you have the thread in the tension disks and that you have it correct in the check spring (looks like a wire hook around tension disk)

If you have checked all this and still have problems - Have you broken a needle when sewing something bulky? The timing may be out and that means you need to take it to a sewing machine mechanic. Hope this helps.