So like you want then probably what I and others have suggested for street shooting; for portraits, get a 55-200mm (or similar focal length range) telephoto (long zoom) lens. With street shooting 18x55 or some similar zoom is probably what you want at first (some places have laws against telephoto lenses on the streets, so be wary of that- telephoto being more powerful zoom) unless you want to bite the bullet and try a prime/fixed focal length lens that won’t zoom in or out. I’ve found on the streets prime can be problematic for wide angle/normal shots at times but it’s still very doable. You can’t like stroll into the middle of a busy street when you’re focusing by moving your body.
The tech jargon is really counterintuitive at first but it’s not that hard to figure out eventually. Just hit the books (google the exposure triangle, someone’s bound to have written something explaining that somewhere online for free) and experiment with setup. With the camera you probably want to learn aperture priority mode first for what you’re doing if my hunch is correct, but don’t be ashamed of using automated modes to start.