afaik travel wasn’t even particularly rare, it was just rare that you’d travel very far. Certainly in england it was expected that you’d travel to london or whatever for legal reasons at least like once or twice in your life, and of course merchants existed.

but also a really significant travel no one tends to mention is going on a pilgrimage to jerusalem! to my knowledge most people managed to do it once, and that’s a massive journey to undertake without modern vehicles!
thankfully since religion was so important back then, pilgrims were afforded quite significant privileges like guaranteed free food and housing and iirc travel from anyone, to the point that pretending to be a pilgrim was quite a severe crime.