Hi Abbey: Welcome to the forum.
A lot depends on your budget - the cheaper the better is not overly precise, and it would help to know what lenses you have right now.
For your camera you would likely want one of the following:
Canon EF-S 55-250 IS STM: very cheap and good optics but will not make the moon massively large in your image
Canon EF 70-300 IS USM (MkI or MkII), excellent optics and will fit a full-frame camera if you ever choose to get one.
Tamron or Sigma 150-600 Contemporary will make moon much larger, but are large and relatively expensive.
(Avoid the Canon EF 75-300 lenses - they are, at best, mediocre optics and have no image stabilization)
I don't live in the US, so I won't venture prices, but you can get the Canon lenses from the Canon refurbished site, where they are basically as new and come with a 1 year warranty, but much reduced in price. The link with a search for suitable lenses is HERE .
Be wary of pointing a camera with a large telephoto lens at the sun, it will bring a very high-intensity light and can damage your eyesight and the camera itself if you do so at anything else that late sunset when the sun is very low on the horizon.
first off and most importantly -- YOU MUST NOT LOOK AT THE SUN THROUGH YOUR CAMERA. Your camera has an optical viewfinder; looking at the Sun through it is like looking at the Sun through a telescope. YOU WILL SUFFER MASSIVE, PERMANENT EYE DAMAGE.
Professional astrophotographers know how to use special filters in front of the camera to do solar photography safely; but even they will not actually look through an optical viewfinder at the Sun, as a basic safety precaution.
Yes you can (and probably have) take Sunset pictures with the Sun in shot, using a regular wide lens. And *very* close to Sunset will be less dangerous. But if you start messing about with a telephoto lens and looking at the Sun, you can literally cook the retina in your eye. Stick to the Moon.
So, let's say you really want to zoom in on the Moon. It depends what you mean by "really zoom in". If you mean a superzoom like some compacts, then forget it, superzooms for your camera -- and interchangable-lens cameras in general -- don't exist. Superzooms exist for compact cameras, where the image sensor is tiny, and the expectation on quality is low. But for larger-sensor cameras like yours, it's a practical impossibility.
So, Trevor has recommended some more modest zooms which will capture a decent image of the Moon; not frame-filling, but they should be pretty satisfying.
If you want to fill the frame with the Moon, you'll want an 800mm lens. But this won't be cheap. Or, if it is cheap, quality will generally be poor.
If you really want superzoom-style performance, you may well be better off with a bridge camera. The quality won't be close to what you can get with a DSLR, but a 50x zoom is quite possible.
If you want more eye safety info, my website has a page on this (for eclipses, but it applies to the Sun in general): https://moonblink.info/Eclipse/what/safety The links at the bottom might help, specially B. Ralph Chou.
Oh and what can damage your eye, can also damage your camera. https://www.youtube.com/watch?v=2TO_yZDxryQ
I understand what you mean; however you still need to be very careful. I know Trevor's pictures are stunning, and they well demonstrate that it is possible to take lovely Sunset pictures. However, the combination of an optical viewfinder and a tele lens is still potentially very dangerous, any time the Sun is visible. You just can't know how clear the atmosphere will be on any given day.
My strong advice is don't look at Sun through the viewfinder; use live view, and compose your shots on the external LCD screen.
I think both Atticus and I are worried about you pointing your camera with a telephoto lens at the sun and doing yourself and the camera irreparable damage. When I say shoot the sun when it is very low on the horizon and relatively dim, I really mean just about on the horizon.
I would recommend using whatever lens you use, on the moon exclusively first - it is amazingly bright when viewed close up, and will give you great results if you get the exposure right - you need to seriously underexpose the image compared to what the camera suggests - it is metering a huge chunk of black sky so it will over-expose the moon.
I think you can do well with a DSLR if you get a good quality lens and get the exposure right. The following images were taken of the moon with the lenses identified.
This is taken with a similar-sized sensor, using the Sigma 150-600mm lens at 600 - but due to a quirk of the sensor size, it delivers an image as if it was 960mm long. As is the one below:
Shooting the moon when it is not full can be very rewarding - the light really shows the texture of the various craters.
Atticus is correct that you could get closer results with a Bridge Camera, although the sensor is small to make this happen and it reduces the resolution. Not to mention it's a whole new camera and I didn't pursue that option based on your comments on investment.
Atticus is obviously well-versed in astronomical photography and I recommend you check out the links he has provided.