Lordsnow6969

What lense should I get to be able to see planets. New to using a telescope, but lifelong interest in space. I would like to see mars, Venus, Jupiter, and Saturn. Of course I would enjoy any other objects in space, but those are first, after the moon. I have a 20mm lense and a 3x Barlow lense. I also have a moon filter. All of these came with the telscope when I purchased it. Looking for ANY Advice on how to use my telescope and what lenses you have used to see everything you've read about in books. Thank you in advance!