Generally, we conjugate the verb 'sein' for any verb that indicates i) movement ii) or a change in state.

For example i) gehen = to go and suggests an act of movement therefore we would have to conjugate the sein auxiliary and use with the past participle which is gegangen. Hence, 'I went' = Ich bin gegangen. (Bin being the conjugated form of sein for the subject ich)

One thing to be aware of is that verbs that indicate a lack of movement also take sein. eg. bleiben = to stay. Hence, 'I stayed at home' = Ich bin zu Hause geblieben

ii) Verbs that suggest a change in state could include einfrieren (to freeze), schmelzen (to melt) schalfen (to sleep) aufwachen (to wake up). Any verbs that mean something/someone has transformed from one state to another. eg. 'I woke up' = Ich bin aufgewachen.