Hi and welcome.
I recently bough my first bike (since I was a kid), and I let the helpful and knowledgeable person at a local sporting goods store help me pick it. I spent less than 200 bucks, and I'm thrilled. Ya, it's kind of a moose, but it fits the description of what I wanted to a T. I told the guy I wanted something for street riding, that could take a child seat, that I could ride everywhere, could use for running errands as much as for pleasure rides.
So I got a great 1st bike for not too much money... That way, when I go back to buy another one in a couple of years, I'll know what features I want from my own experience, and then, and only then, will I be prepared to shell out some serious bucks for a really incredible bike. And after training on my behemoth, I'll kick some serious tail on a lightweight bike! 😉
Go to a professionally staffed store, get their advice. Don't let 'em sell you a fancy bike to begin with.
Have fun!
Sara