I've had three babies and being mobile was really important to me, and I found it bearable. Not the most fun I've ever had, not an experience I'm keen to repeat a fourth time TBH, but absolutely bearable, especially with DC1 and 3 where I did quite a lot of prep (I naively thought with DC2 oh I'll be fine I've done it before.)
For the majority of midwife led units in the UK if you change your mind and want an epidural they can transfer you to the consultant led ward which is usually nearby, often even in the same building. They have to have some access to emergency caeserean surgery for example so other interventions are generally available, the main risk is that you might have to wait longer for an epidural if you decide in the moment and you have to both be transferred and wait for the anaesthetist to be available, and with both of those delays you have a higher chance of ending up where it's too late and they can't do it. But IME planning for a birth without these things leaves you in a better space in case something like that happens or for whatever other reason it is unavailable.
The main thing I would say to avoid is the mindset that if you can make yourself calm enough or relaxed enough that you can control how the birth itself goes or how much pain you experience. This is a mindset where if for whatever reason, which might be completely out of your control, it doesn't work as you expect then you can end up feeling as though you have failed which is enormously painful and difficult and can be traumatic. And TBH - I actually think that even if everything goes well, childbirth has aspects which can be traumatic. I don't say that to be scary, I just mean to say don't add on expectations for yourself which have a possibility of "failure".
The better mindset IME is focusing on tools you can use to help yourself through situations which can be overwhelming, tools which help you for example remember that a contraction is short, or which feel productive, or which can help you to retreat to more of an inner place (which sounds woo but will make more sense when you've actually experienced labour). The very best book I read was Birth Skills by Juju Sundin and I think this is so brilliant I recommend it to everyone. There is also a good youtube channel by an American L&D nurse called Sarah Lavonne.
I think it can be helpful to learn a bit about different interventions and why they might be offered and what it might mean in advance. But TBH it can also be a hindrance to know too much, because some interventions sound scary (I was terrified of the idea of an episiotomy) but they really won't be doing things just for the sake of it - midwives are trained to support you to try to avoid the need for intervention, and when intervention is suggested it is usually because it is the better of two bad options at that point, and so sometimes it's best not to really think too much about it, because if you are at that point then usually it's something which makes sense anyway.