First time sex🤷‍♀️

So me and my bestfriend of like a year me and him are super close and all and like I can trust him , I made a joke about us having sex and he told me he was actually thinking about us doing it and we both wanna lose it and get it over and done with and I feel like because we’re so close if anything goes wrong we’ll just laugh it off later but idk it might be really awkward because we’re friends we have sent each other nudes so we’ve seen each other like that already ,I’ve never fingered myself or used tampons so I’m scared when we do it it’s gonna hurt like a bitch because nothing has been up there and he’s quite big , so what should I do to prepare myself so it’s all good and goes well and does anyone have any good advice that can help me