Originally Posted by
AnnaCA
...Easiest by country mile is to get the HSL app on your phone, route planner on that is pretty decent as well as obvs being handy way to buy said ticket.
Doesn't HSL app require internet connection?
OP seems to be NA, ie might be hit with huge roaming fees or having to get local SIM.
But if not, it can be highly recommended even for foreigners as the payments issues have been sorted and one can pay by non-FIN issued credit cards.