Spells don't need ingredients or supplies. You can use a simple incantation, or, if skilled enough, simply send out your intent. You can also write your own spells, and use supplies you already have in your house. However, due to the fact that you did not already know the aforementioned information, I would recommend reading about magick before attempting to write or cast any spells.
As far as pregnancy spells, a spell alone cannot cause pregnancy. Many people claim that a spell can make it more likely, but you still have to have intercourse during ovulation for it to be possible.