Hi there.
Not to be obtuse, but the way you phrased your question doesn't lend itself to easy answering. If you're trying to ask about how much could a 'person from the middle ages' could cover in terms of sheer distance, that would depend entirely on whether he was traveling by foot or by some other means of transportation. The exact distance one could possibly cover by walking/horse/wagon/ship/barge varies from region and season, but general ballparks exist.
Now, if you're asking whether the 'average person' had any inclination or need to leave his/her town/village, then the answer is a fairly strong 'yes'. Barring Russian serfs who were (in some periods) not allowed to leave, the people in the middle ages did travel. In many cases, a pilgrimage to some sacred site or 'tourist attraction' would totally be doable for the 'average person'.
Here's an excellent piece from /u/sunagainstgold, detailing just such a thing.
In addition, if you were inspired by depictions of traveling adventurers in fictional works, and was wondering if it really worked like that, here's a nice piece by /u/vonadler that might be relevant to you.
Cheers.