Yeah, give it about a year before thinking about upgrades. Takes awhile to build up a solid fitness base.

We have no mountains here, just roller coaster terrain with lots of short, steep hillettes. And I don't race so sprinting isn't a factor unless I'm chasing a PR. After reviewing my Strava data over the past few years, comparing my 24 lb steel road bike and sub-20 lb carbon fiber bikes, I see no consistent differences or advantages to the carbon fiber bikes. I've tied my best times on some tough segments using all three bikes.

The best and most cost effective upgrade I've done to all my bikes is better tires and latex tubes, or the lighter Continental Race 28 Light or comparably thin butyl tubes. Latex tubes really enhance the road feel of good tires. They may be a bit quicker, but they are definitely more comfortable on chipseal and rough pavement, which can't hurt my chasing PRs.

Ditto, more aero position on the bike, aero clothing, helmet, etc. Those are cost effective methods for gaining a little speed. However it doesn't help as much on climbs unless there's a headwind, or my average speed is better than around 14 mph, which is pretty rare for me on climbs. Any consistent gains I see from getting more aero is measured over distance in which flat terrain, uphills and downhills more or less even out the ride.