What things did the crusaders face on their way?

It was not so much what they faced but more what the people on the road that the crusaders used face when the crusaders passed them. The crusaders has also been known to plunder on their way to the holy land.

But the crusaders had to deal with Muslims that intended to stop or kill the crusaders on their way to the holy land and not to mention that it was a 6 month journey. They also had to cross the Alps and Many deserts. So the elements I would say was their greatest challenge.