We recommend having the bike inspected by a professional mechanic after the first 60 miles of riding and every 300 miles after. The service intervals will greatly depend on the riding style, terrain, and weight. For example, electric bikes with occasional riding will be good for about 300 miles. If a rider chooses to take a bike offroad, service will be required more frequently as more parts will wear faster in the harsher terrain.
One way to keep your bike in top shape is to keep it clean, never fully discharge the battery, inflate the tires, and make sure the chain is clean and lubed. This will ensure metal on metal contact will not happen. It also will keep rust from developing.