Vaishno devi mandir is located in katra at the trikuta parbat. This part lies in the jammu region of jammu and kashmir state. As I am also from jammu so you can trust me undoubtly.
ACCESSIBILITY: there is a train service upto katra but if you want to explore jammu city also then you can first stop in jammu and then can take the bus from jammu to katra . It will take around 1 and half hours from there or you can take helicopter ride also that will directly drop u to the sanji chatt area(upper part of mountain).
HOTELS: there are many hotels in katra city so you can book one and keep your luggage over there and the charges are also very cheaper.
JOURNEY: the total distance is about 12-13 kms from one side upto the top. you can take the horse ride or can take a walk. Its gonna take u around 7-8 hours to reach the bhavan if u take a walk.
LOCAL SIGHTSEEING: you will see a lot of temples there, in between comes the baan ganga where u can take a holy bath and also the beautiful mountains and animals. The sunrise is also a totally different experience there.
there are langars also or you can buy food at cheap cost and after reaching bhavan u can take the bath in the water coming directly from the mountains. After darshan u may head towards the bhairav ghati which is 2.5 kms away.
TIP: if u want to enjoy more then go in winters around january. At that time there is snowfall but dont forget to carry your woolens with you and blanket also.