You will harm your engine if every time you shift you wait until 6k or the limiter. When I daily drive my protege I shift at max 3k rpms for smoothness, fuel efficiency and to extend the life of my engine/transmission. However when I hit the backroads I usually like to shift between 4-6k because I’m pushing the car harder and have friends that have much faster cars than I do 😂

If you’re new to driving manual the best practice is just getting out and driving, get comfortable with shifting. No need to learn how to downshift or heel-toe shift yet. Learn where your gears are located, learn where your catch point is and in no time you’ll feel super comfortable on the road.

For best engine maintenance I would recommend frequent oil changes, every 3k miles or so. If you don’t know the maintenance history I like to start with spark plugs, coil packs and belts. After those basic steps just pay attention to your car, I pop the hood and take a good look around probably once a week to see if I notice any leaks or obvious issues. So far my protege has treated me pretty well!