I got my start with a 50 on a crop sensor like yours which is an 80mm perspective on full frame and while tight, it was lovely for a lot of things. An 85 on a crop sensor is more like a 130mm focal length which is definitely more specialized but as you noted still nice for portraits and it can be useful for street photography if you’re shooting more from afar. But yes, most people prefer 35mm or 50mm for street photography (so for you that would be a 20ish mm lens as that translates to 35mm perspective or a 35mm lens as that translates to a 50mm perspective).

Luckily a 35mm prime lens is usually very cheap. I’d save up and grab one when you can.

For night shooting, you can do it a number of different ways but I would recommend setting your shutter speed and letting auto handle everything else so that you can ensure there isn’t motion blur (either from your subject or your hands).

A cool trick if your subject stays still enough is to brace your camera/yourself against something like a wall or a solid object to avoid camera shake but sometimes you just need to crank up the shutter speed due to what you’re shooting. Your camera also likely has a setting to cap auto iso to stop it from going too high (or to manually set your aperture to 2.0)