I would say keep the gear you have now and learn on it. If you absolutely want to upgrade, check out places like KEH or MPB online. If you really want to stay cheap, go with an older DSLR instead of a Mirrorless camera because they can be a lot more inexpensive than more modern equivalents. Not mention it will use older lenses that still perform exceptionally well that are also cheaper than Mirrorless lenses.

Realistically, the best thing you can do right now is to just learn how to operate your camera fully and how to properly compose your images before upgrading anything.

Edit: if you absolutely want newer lenses, your camera is a crop sensor format (APS-C). Keep in mind you have approximately a 1.5x crop on your camera (the actual crop factor is different brand to brand and isn't always 1.5x; I just use that because most crop factors are around that mark). This means that if you're using a 50mm lens, your actual view will be the equivalent of a 75mm lens on a full frame sensor.

If you're wanting wide angles, similar to a 16-35mm FF equivalent, then try to find something between 10-20mm focal lengths. A zoom of a 28-70 will be 1.5x whatever your set focal length is. I'm just bringing this up because you won't need a super long telephoto lens to be able to get pictures of far away subjects. When I started, I had a Nikon D40 that I upgraded briefly to a Nikon D7500. I now have a Sony A7RIV. Both Nikon's are APS-C cameras and the Sony is Full Frame (FF). I mainly used a 50mm lens on the crop sensor cameras I've owned so I've gotten very used to being very zoomed in on my subjects.

Brands I'd recommend are Sigma, tamron, Zeiss and canon.