I got oral sex from a person who now has strep throat, should I be worried about anything?

Nothing horrible. You could get genital group a strep from this. In general this doesn't happen to post pubertal patients but if you start with discharge, redness, painful urination or are just concerned get checked out. It is easy to diagnose and easy to treat.
No. Generally, streptococci do not cause std. However, impetigo and other skin infections can be caused by streptococci. So if you have a sore, scab or pustule (pus in a bump) on your genitalia, you should be examined.