Hi,
Congratulations on your new scope. I am sure you will have a lot of fun with it. I got my first scope when I was 11 and 52 years later I am still playing with them
I wouldn't worry about the moon filter if you haven't already ordered it. No filter adds anything, moon or otherwise, it only cuts things down, generally what you don't want. You will see more detail on the moon without a filter than you will with a filter. While at first instance you might think the moon appears very bright and might cause eye damage, just remember you are looking at the suns light reflected off a surface similar to a bitumen road. When sunlight reflects off the road you don't even see it because your surroundings are so bright. Conversely, the moon only appears really bright because the surroundings are so dark. I observe the moon unfiltered in my 10", 14" and 18" telescopes. After you look away from the eyepiece you get "red eye" for about 30 seconds but that quickly dissappears as your eye adjusts.
If you have little kids I can understand they might find the "apparent" brightness a bit off putting. If you have little kids and need a filter for the moon, I would suggest a variable polarising filter as opposed to a dedicated Moon Filter which is just a Neutral Density filter. Some moon filters block out more light than others, but they are fixed. There is no adjustment with a "Moon Filter". For instance the Orion Moonfilter blocks 87% of the incoming light, which with a 5" telescope isn't what you want. A variable polariser costs a little bit more but is fully adjustable and can be adjusted to block out between about 5% and 40% of the light. This will be a much better option in combination with your new telescope.
Here is a link to a presentation I gave on
Visual Astronomy and the Use of Filters at the Ice IN Space Astrocamp in 2011. The bit about Moon Filters and Variable Polarisers is towards the end.
Cheers
John B