I'm not looking to get into professional photography, just wanna take decent nature pictures and shoot decent nature vids for fun, they don't need to be AMAZING pictures.
Being a guitar player can be kinda expensive too, yet i haven't had any problems with that, money wise. You just save up money for whatever you need, even if it takes a while. I don't see what the big deal is.
If you grow up broke, you kinda learn to save up.
Do not worry, Nikon 18-55 kit lense is very, very good, it punches way above its wight and price tag. As a value for money high quality versatile camera 3xxx or 5xxx "baby" Nikon DSLR is impossible to beat these days. You can buy it with confidence. And later on when you have some spare money you can add more lenses. But as a start D3xxx with 18-55 is an excellent camera.
Yes, the 18-55 "kit" lens is a decent enough lens. In fact, I still use mine a good bit. I have "better" glass, but don't really have anything below 28mm, so if I want a wider focal length, I wouldn't hesitate to use my 18-55.
However--it is NOT really going to be effective for much in the way of nature shots, certainly not for "clear shots up a tree" or "recording birds in the sky." You shoot birds in the sky with an 18-55, all you're going to get is a lot of sky and some little dots.
I'd also disagree though, that you need to pick a different hobby, if you can't afford much. I started this hobby as a broke single mom! I started with a D5100 and the 18-55 lens. I VERY slowly added other lenses as I could, and just worked with what I had.
Yes, only having the 18-55 will limit you, fairly severely if you're wanting nature shots. But, you can at least start learning, and then add what you can, as you can.
If nature is what you're really interested in, I'd HIGHLY recommend the 70-300 f/4.5-5.6 lens, but it might be out of your budget, even used. If so, look into the longest focal length you CAN get in your budget. At least 200mm, 300mm would be better. I started with a 55-200--it was NOT a great lens, but it was cheap and I learned some things with it. Then I got a 55-300. It wasn't all that great either, but it was cheap, and longer than the 200mm. Then I got the 70-300…and, for the price, it is a SOLID lens. I still use it, sometimes, even though I now have a 150-500 lens and a 70-200 f/2.8 lens.
Point is, buy what you can afford to get started, but just realize that if you're wanting to do much in the way of nature stuff, you want as long a focal length as you can afford to get.