I love hearing new riders' stories. I had so much fun as a beginner, with something new to learn every day. I love bicycling and I always will, but I am a little nostalgic for when it was all new and shiny. (I still have much to learn, just not every day.)
Does your bike have gears? Use the lower gears. Many beginners like to "mash" the pedals, which wears you out quickly and is hard on your knees. Try to be a "spinner", where you turn the pedals easily & quickly, using your lowest gears.
If your bike has coaster brakes, it might be a single speed without gears (single speeds & coaster brakes often go together). Is your town flat or hilly? If your 5 mile commute is hilly, you might be more comfortable on a bike with gears.
I prefer to around speed bumps. But if I have to go over, I lift my butt off the seat.
Check your helmet for visible damage. It's best to just replace it after it's taken a hit, but definitely if there's visible cracks.
TE is such a great resource. No question is stupid on TE. We've all been there & we love to share our experience overwhelmingly.
Have fun, and good luck!
2009 Trek 7.2FX WSD, brooks Champion Flyer S, commuter bike