Taekwondo, Karate, Judo and MMA can be an amazing sport to participate in, however it can be very dangerous. There are three major things to always consider when enjoying the art of karate.
First and foremost, you should never spar without a sparring gear set!
That is your protection and you absolutely need it!
Secondly, you should keep your elbows in and try to relax and enjoy it. Being too uptight can cause you to have bad reflexes. Lastly, do not over do it.
Practice makes perfect but if you practice too much you can cause your body to be too tired and that can cause injuries.
Make sure you stay safe while you practice and always use your sparring gear sets.