"Upgradeitis" is endemic to all roadies, maybe even all cyclists. Lately, I've been spending decent money on a custom cruiser of all things.

Anyways the fact, as others have said, is that the bike in your budget is more tha suitable for your stated goals and well beyond.

If the bike fits you (critical), the wheels are true, the bearings smooth, the shifting is reliable and the brakes grab the bike will do 90%+ of all you will ever be able to do on a bike. Get your bike and get started.

Having said that, upgrading is fun. Expensive but fun.