Can I a kid be on this site and ask Questions? I want to but I think they would be silly
Apart from that, you're welcome to ask whatever you like. Keep in mind that we'll hold your questions to the same standards as everyone else's --- that is, we won't treat you specially because you're young --- which may mean that your questions get downvoted or closed for reasons that aren't obvious to you.
Yeah, you can. (As long as you're 13 or up, as rob said.)
I'm a kid too (ahem, teenager, but whatever), and I love this site. I've asked some pretty darn "silly" questions (or at least, ones I thought were silly) but no one has treated me poorly (or differently, for that matter) because of my age. Once you get enough rep, check out the hbar - lots of people there are willing to help and have helped me.
So, give it a go! Learn physics and math and whatever else you may be interested in, and use this site to help you out! You never know what you might learn along the way.
I started using this site when I was around 16, because I had already studied topics up to quantum field theory, and did not have people that could help me except those online.
I found the physics SE was a great resource, both the existing questions and the body of experienced users that were able to address mine. I also got a lot of satisfaction from helping other people. I was never treated any differently because of my age.
As others have said, it may take you some time to learn how to formulate a question that will be well-received and fit all the guidelines, but I and I am sure other users will be happy to provide any support. When we downvote or close, we give suggestions for improvement.