Can you still contract an STD if you have protected first-time sex?
If you have protected sex with somebody and it is the first time either of you has had sex, then the chance of contracting an STD is pretty close to zero. There are a couple of STDs that can be contracted non-sexually, so it is remotely possible that one of you might have one of those. The most likely would be oral herpes, which is usually transmitted by kissing. The other one is HPV, which can be contracted non-sexually as well. Other than those two, there is almost zero chance that either of you would have a disease that could be transmitted to the other.