Two ways of doing this, and depends on your subject.
1 Attaching the camera with lens to take an image of what's in the eyepiece (eyepiece projection). Use this for small bright subjects like planets.
2 Attaching the camera without lens direct to the eyepiece tube with no eyepiece (prime focus). This is for larger, less bright subjects eg galaxies, nebulae etc.
Either method need adaptors. I don't do eyepiece projection but for prime focus you need a tee ring which slips into the eyepiece tube and has a thread on the tee end. I've just looked up your scope and now I see what you mean about attaching to the end of the scope tube - slightly different to any scope I've used but the same principle. You need to buy the tee adaptor specific for the scope if you don't already have it. This screws into an adaptor specific to your camera mount (Canon in your case). Some scopes need a low profile adaptor to enable the camera to focus. The easiest ones to find online are quite thick but if you search specifically for 'low profile' you'll find them. I don't know which type you'd need but they're not expensive if you get it wrong.
Your scope is small and on an alt az mount so it's not suitable for serious astrophotography. I don't know how large the Moon will appear in it so I can't help on which photography method would be suitable. To be honest, though, you don't need long exposures or a tracking mount to image the Moon. If you have a long lens on a fixed tripod it's much simpler than messing about with a scope. Manufacturers like to make out that photography through a scope is simple but it can be a real pain until you've done it quite a few times. However you do it, take a number of images. There'll be a certain amount of atmospheric disturbance which will be magnified by a long lens or scope, which can make the image lack sharpness. Take several, one after the other, and hopefully you'll find a good one among them. I have a project going shooting sunspots and do exactly the same. I'll take a dozen or more to get one image I'm happy with. If you fancy looking at my Flickr, there's an album called Astronomy with images taken using a variety of different methods and equipment.
The eyepieces you get with budget scopes are rubbish, but I'm not sure about getting a zoom. Fine for observing bright things (the Moon) but for fainter stuff you need all the light you can get, and anything you do with light - bend it, reflect it etc - loses a bit, so the less you deflect it the better. Scopes are a bit like cameras. So long as the scope's optics are decent (and modern ones are) it can be made or broken by the eyepiece. The same as investing in good lenses rather than a camera body, it's worth having just a few good quality eyepieces in 2 or 3 sizes that are right for your scope and what you want to see. Start with a wide field (big number/big hole) and don't be tempted into something that's going to give too high a magnification. It'll render the subject much darker, harder to see, harder to focus. It's only a 4 inch scope so stick to big and bright. Manufacturers don't like telling you the limitations of their scopes and you'll have lots in your object database that you just won't see. For kids, though, it's a nice little scope to just look through, so get it out for them and use it. I had my little 150mm reflector out at a school thing the other week showing about 100 primary school kids and parents the Moon. Freezing cold, stressful, watching the scope like a hawk the whole time as kids will walk into it and put their sticky fingers all over it, but their reaction (Wow! Cool!) is so worthwhile.
