“Does everyone have access to a rav who is at such a level that one can totally be open with him and he will certainly provide Ruach Hakodesh?”
probably not, but then you should be aware that the Rav you are speaking to is not on that level and don’t assume that he can tell you who you should marry or that you should believe him if he does tell you.
The Talmidei Chachamim in each generation know who the Gedolim are and the Gedolim of each generation know who the other Gedolim are and who the Gedolim of the next generation are.
Even if you don’t have access to Gedolim, you should be able to find a Rav who does.