Every birth is different. It can be empowering, scary, visceral, shocking, hilarious, fun, all in the one delivery. I remember at 37 weeks with my first child having a similar reality check moment, that this was really going to happen and I didn't known how it was going to go, what exactly was going to happen on the day, how it would feel and how I would manage.
What struck me most in your post was the words 'pain free'. Birth is very very unlikely to be totally pain free. It is painful, or at least was for everyone I know and have discussed it with. Contractions are painful for most people, but they serve a purpose and for some women are really manageable. Delivering the baby hurts but it is also over relatively quickly in the scheme of things and for many women is an incredibly empowering experience. And many, many women manage the pain with minimal or no pain relief (eg gas and air) and some women don't tear at all while others have tiny tears. It depends on so many factors - some are in your control but many are not. The baby's position can have a huge impact on how painful it is and there's not all that much you can do about that. The experience of the staff helping you deliver your baby can have an impact.
It sounds like you've done everything you can to prepare. Going in with a positive but pragmatic mindset is probably your best bet. To a certain extent you have to give yourself over to the process. It's very primal. I have two dc, one born 'naturally' (in quote marks as I went in hoping to stick to gas and air and have a water birth but in the end was induced, had an epidural, ventouse, episiotomy plus big tear) and one born by elcs (wonderful birth, painful recovery managed with pain medication). My birth experience with my first dc was the most visceral, intense, primal, extreme experience of my life. It still amazes me when I think of it, 6 years later. It was great and amazing and painful and fun and awful and astonishing and shocking and thrilling. Extreme. I think most births involve many of those moments all mixed up together.
Many women do tear but it generally heals well. Many women do find it much more painful than they imagined and have pain relief when they didn't expect to - but personally I'm thankful we have that option. Your birth with be different to everyone else's but similar. You may well need some intervention but you'll be ok. It'll be different to what you expect, probably, but then the key is to keep your expectations a little vague! Good luck!