I just started bike a couple days ago and want to make sure I'm starting out on the right track. From what I've read in other posts, beginners like myself, do <60 rpm. I have been riding on the highest gears possible (resulting in a lower rpm), should I keep it that way, or should I lower the chain ring and cassette to concentrate on spinning?
Most cyclist recommend more rpm's. Go in a gear that gives what feels like almost no resistance on your foot. If you ride at lower rpm's and need more force you will exhaust your leg muscles and have nothing left for hills or sprints.
Get used to 1 hour riding at 15 mph then move up from there.
Gradually increase your cadence, aiming for 85 or more on the flats, 70-85 climbing. A bike computer with a cadence feature (like a Cateye Astrale) is a huge help. At first it will feel like the strength is rapidly going out of your legs when you ride and especially climb at these cadences, but you'll gradually improve. Most people I ride with tend to do 90-100 on the flat and 75-85 climbing. Of course when you run out of gears climbing steeper hills, your cadence will have to drop to suit whatever speed you can sustain.
It's no different for a beginner. The sooner you get used to higher cadences, the faster your riding will improve. You might also think about a heart rate monitor (HRM). Beginners especially benefit from using a HRM. Many people I ride with started with one, and then discarded it when they got used to what it's supposed to feel like.
Its a mongoose pro morzine road bike....I've started spinning since yesterday, and its funny because i feel like i'm starting out much slower, but it feels better on my legs in the long run.
An issue I'm having though, is that theres lots of small hills, and I have to constantly change gears.
Exactly. And what you're saying about gear changing is the reason modern bikes have those combination shift/brake levers, sometimes called brifters. Most riders spend about 90% of the time with their hands on the brifter hoods so their fingers are constantly in position for gear changing and braking.