Yeah. It sounds different when a guy vs. a female bodied person pees. I'm very self conscious of it myself. I have an stp, and I highly recommend it. Making one out of a turkey baster or funnel isn't hard at all, and paid off for me. It still makes me all giddy inside even these days, to walk up to a urinal, whip out my stp and take a normal leak like other guys. But really, if you pee slow, it'll be fine. No one is really judging the sound.
About using the men's room...just strut in like you belong in there like any other guy. I think half the challenge of passing is how you hold yourself, how confident you act. If you act confident, people tend not to question you. It eminates in the energy you give off, your posture, etc.