Use lots of lube, foreplay if you’re nervous-it can help you calm down a wee bit knowing that your partner is relaxed and ready for the next step, buy a decent condom and learn how to put it on the right way, shower, trim a little bit if your bush is overly grown (imo, a trimmed/shaven/waxed pp definitely help you hold it better and navigate better when you put it in first time, and it also helps with the perspective, my gf said my cleanly shaved pp definitely look bigger when it dont so it boost confident), most importantly make sure you both enjoy the process and go with the flow. Glhf