Does this make any sense? Need help with imperfect!
"Mientras estuve alli, fui a Hollywood, acampaba en las montanas, y comia en muchos restaurantes." I don't know if I am using the imperfect or preterite incorrectly... I really need to have more imperfect verbs. Please help!! 
2 Answers
If you are simply listing things that you did and were completed in the past, use the preterite.
I went camping, I ate in a lot of restaurants, I went to Hollywood, etc.
If you are discussing things that went on during your entire stay or happened repeatedly then use the imperfect
While on my trip is was always eating in lots of restaurants, I was camping the whole time in the mountains, I visited Hollywood several times, etc.
You chose the tense to express what you mean. Either you want to state that you did something placing no starting, ending or duration emphasis on the action or event or you state it as something that specifically started, ended and was completed at some time in the past.
A common use of the past tense is to tell about an event that happened in the past while something else was going in.
I was home watching TV when someone knocked on the door. Watching TV is imperfect since we're not interested in when it started, ended or how long it occurred. The knock of the door has a start, stop and duration aspect to it so we use the preterite. To show how subjective it is, we could then discuss how the telephone rang and the person keep knocking on the door all during the telephone conversation. Then the knocking is imperfect and the telephone ringing is preterite. The verb tense choses depends on what you wish to say with the verb and tells us whether you want the action to paint a background or just be an event that occurred, ended, then another event occurred.
The best analogy that I have ever heard is the imperfect is like a video showing clips or movies of past action while the preterite is a camera showing still photos of the past.
I think that the first part has to be "Mientras estaba allí" because that tense, the imperfect, can be used - as I think you want to use it here - for an action that is going on..continues..and in fact is the background for another action.
