Here you want to use the preterite form of the verbs estar and ser. For the first sentence you want to use estar because estar is used when talking about health, emotion, location, or progressives. And since you are talking about where you were in the past you need to use the preterite tense yo conjugation of estar, which is estuve. For the second sentence you want to use ser because you use ser to describe date, origin, characteristics, time, occupation, and relationships and coach is a occupation. And again you are talking about yourself in the past so you use the preterite yo conjugation which is fui.
