I still think sex is something married couples get better at as they go (if they both want to, and I would argue that they should want to). They do that precisely because of their commitment and true sacrificial love. They should want to please their spouse, so they make an effort to learn how to do so, and anybody can learn how if they are willing to communicate - which you mention is also incredibly important.
And yes, there are skills involved in learning how to eat, though many of them become second nature to us very early. Married couples who do things “the right way” can also have those things become second nature pretty early.
Basically, what I am saying to the OP is that if she and a prospective spouse really want the best for each other, their sex life will be fine - because they’ll adapt to each other and learn together. I am not advocating a “test drive” at all - not sure if you were directing that at me or the OP - just that she should expect that the sex part of the marital relationship should fall into place if she picks a good husband and is willing to be a good wife.