The Poles use two separate verbs of motion; one refers to movement by foot and the other is used for movement on transportation, like buses and cars. Both of these verbs are irregular, which means they fall outside the generic pattern of conjugation for polish verbs. You will need to look out for the different verb endings for each subject and any irregular stem changes that occur. Furthermore they are often used in conjunction with a preposition, helping to further refine the expression of ‘where’, ‘from where’, ‘to what’ or ‘from what’, so on and so forth, that the subject is moving. That said, the really important thing here is that you are able to use the correct verb in the correct context; differentiating between movement on foot and other types of transportation

Movement on Foot (Iść)
The Polish verb that expresses movement on foot is iść, which, being an irregular verb, will change both its ending and its stem when we use it to refer to a particular subject (like 'me', 'you', 'them', 'we', or 'they'). Let's take a look at how we express movement for each of these, and what endings are associated with each:
idę: I go (on foot).
idziesz: You go (on foot).
on/ona idzie: he/she goes (on foot).
idziemy: We go (on foot).
idziecie: You [plural] go (on foot).
oni/one idą: They go (on foot).
Hopefully you can see how the stem change occurs alongside the ending conjugations, and once you've got the hang of that, you will be able to express this type of movement for the range of subjects.
Movement on Transportation (Jechać)
In Polish it's the verb jechać that is used to express movement by transport. Like iść, it is also irregular, so keep an eye out for those stem changes as well as the generic verb ending conjugations.
Jadę: I go (by transport).
Jedziesz: You go (by transport).
on/ona jedzie: he/she goes (by transport).
jedziemy: We go (by transport).
jedziecie: You [plural] go (on transport).
oni/one jadą: They go (by transport).
Notice how the stem changes that occur for each of these verbs follow a similar pattern. The first person singular and third person plurals both adopt the same stem form, while all the others have their own consistent pattern.
Usage Examples
Some clear differences in usages will be between international travel and local travel, where the former makes transportation by foot impossible, and the latter means it is much more likely. Compare these two questions and answers :
1.Question: Gdzie idziesz? (Where are you going [walking] to?)
1.Answer: Idę do domu (I am going [walking] home)
2.Question: Gdzie jedziesz? (Where are you going [travelling] to?)
2.Answer: Jadę do Polski (I am going [by transport] to Poland)
Things Worth Noting
When referring to social activities like visits to the park or the cinema, it's almost always iść that is used in Polish, regardless of whether the trip will include transportation other than walking. In these instances jechać is only used to refer directly to the journey to and from the event.
In English, a common source of confusion for non-native speakers is our usage of the present simple tense for planning future activities. These two verbs are prime examples of how precisely the same thing can be done in Polish: Idę jutro do Muzeum (tomorrow I am going to the museum).
You may have noticed that many of the nouns used in the examples above have had conjugated endings (jadę do Polski/idę do domu). When we are talking about location and movement in Polish, this is often to do with the preposition (words like 'of', 'to', 'from' etc) that is associated with the movement of the subject, and these are conjugation rules that will need to be learned in separate grammar study.