“I did not go” or “I did not went”?
“I did not go” is correct.
“Did” is an auxiliary verb, also known as a helping verb and indicates the voice, tense, or mood of the main verb. In this case, your sentence is the simple past tense. The main verb, “go” must be in its infinitive form, which just means its most basic form (present tense without a special ending).
In other words, the tense of your sentence is controlled by the auxiliary verb “did.” The following verb “go” does not need to change forms.