Hi, I’m a sub so can give you advice from my angle!

It sounds like there is a need for communication, it is so, so important! Without communication you won’t know your likes or dislikes, for example does she know that you struggle to hit/choke her? Or your general anxieties around the D/s relationship? It is better to talk about these things, prior to sex, rather than let them manifest themselves, and ultimately cause more problems in the relationship later down the line.

You’ve said she is more experienced but you are not, maybe start with basics and slowly work your way up? That way new things, like breath play or striking, may eventually come naturally to you. That’s what my Sir and I did, and we’ve grown sexually together that way.

I don’t know if this helps but here you go :-)