I just bought a celestron 130mm nexstar slt...what is the best eye pieces and filters to view with?

That telescope comes with a 25mm eyepiece giving 26x magnification and a 9mm eyepiece giving 72x magnification. You don't need any filters. Use low magnification on the nebula, which is large in size but dim, and high magnification on planets, which are small but bright. Be aware that higher magnification makes the field of view smaller which makes getting the telescope pointed more difficult, so you may want to find Saturn with the 25mm and switch to the 9mm after you have it in the field of view. Do that carefully so you don't move the telescope while changing eyepieces.