«идти»/«пойти» are imperfective/perfective couple of verbs. There is a huge amount of information about verb aspect in Russian. It does not specifically relate to the verbs of motion. Very roughly speaking «идти» is an equivalent of English indefinite and continuous tenses and «пойти» is for perfect tenses.

«ездить»/«ехать» are both imperfective but the former is iterative while the latter is progressive. This is already about verbs of motion specifically. «ездить» (iterative) usually is about performing races from time to time. «ехать» (progressive) is about being in process of racing at a given moment of time.