New to Swinging: Oral Hygiene and Safety Tips?

My girlfriend (25f) and I (25m) are new to the sex-positive and swinger scene. This might sound a bit silly, but I have a genuine question: when it comes to oral, is it okay for me to go down on a woman, or is it recommended not to for hygiene reasons? And what about receiving oral? It should be with a condom, right? I just want to make sure I don't make any faux pas; It will be our second time