Will I get hurt?
Karate does involve physical contact, and you have to be very lucky or extremely good to avoid the occasional bruise in your Martial Arts career.
The instructors are very aware of the potential for injury and constantly strive to promote technical excellence and self control to reduce the risks.
Because of this Karate has one of the lowest injury rates of all "sports", much less than Rugby or Football.
If you work hard you will probably ache after your first few lessons as you utilise muscles you didn't know you had. Actually, if you work really hard you will ache after most karate sessions!
Also, sometimes you need to feel the pain of a technique (such as a pressure point strike or joint lock) to appreciate how it works and how effective it can be. These techniques are usually reserved for higher grades and are applied very carefully and with full consent.