Very little to worry about on the whole as long as you are sensible.
A sturdy, easily adjustable stand is essential, and a snug-fitting dust cover will protect the keys and keep dust away from the electrical contacts. A good quality carry case will pay dividends when the keyboard needs to be transported any distance e.g. when taking examinations, or just being transported to lessons.
The usual manufacturers' warnings about using abrasives etc. on the case should be heeded, and it is best to avoid polishes such as Mr Sheen etc. These tend to leave a film over the surface and being a spray, can easily penetrate into the interior of the instrument. Any dirt on the surface can be removed with a well-wrung cloth that's been dipped in warm water containing a little washing-up liquid. One word of caution when handling power supplies - if it's necessary to move it from place to place quite often, try to resist the temptation to wind the cable around the power supply as the wire will become twisted and will eventually break. Similarly, never pull on power chords or connecting cables - always grip the plug.
NEVER pull out the power chord or switch off at the power supply without first having switched off the keyboard with the button on the instrument and waited until the LCD display has gone blank. Many keyboards write information into memory at this point and it can easily be corrupted and rendered useless if this is ignored.