Sounds strange to my ear. "idę" is going on foot, so it is as if you went to the nearby town on foot for your vacations, but that would be a surprising thing to say even then... it sounds more as if you were talking about 'taking a vacation from work', but that's rather "urlop".

Unfortunately, it's not safe. There are too many things to take into consideration here.

As for being somewhere (at the station), you can either use "na" + Locative or "w" + Locative. The general rule would be that "na" is used with more... open spaces (na stacji, na lotnisku), and "w" with closed ones (w sklepie, w szkole). But the number of exceptions will not be small, so that is just a very general rule of thumb.

Similarly, when going somewhere, you can either use "na" + Accusative or "do" + Genitive. The rule of thumb is the same and is also not very strict. "na stację", "na lotnisko", "do sklepu", "do szkoły".

"Jadę na wakacje"... well, it's just a fixed phrase. "Jadę na motorze" - well, you are 'on' a motorcycle when you ride it, right? So it is literally 'on'. Similarly 'na rowerze'. But if you take a car or a bus, you are not 'on' it but 'in it'. You rather won't say "Jadę w autobusie" (I am going/riding in a bus), you will say "Jadę autobusem" - use Instrumental, as you 'use' the bus like some kind of an 'instrument'.

I think this really is the "I'm going on vacation" one. Your interpretation would have to be more specific in Polish.