Hi,
1.For his next presentation he knows he must be prepared, organised, and able to accompany his presentaion with visuals
2. I used time well ( or productively or efficiently all 3 are OK. Perhaps 'productively' in this context) during each class, and as well I gathered information pertaining to the topic at home, when necessary.
3.He presented his findings in an interesting and organised way which enabled(or inspired different meanings ) us to compile informative( notes on functional fitness.
4. Her aspiration to achieve excellence was evident(or obvious either. 'obvious' seems stronger ) in her seeking feedback to improve her work and spending a lot of time to create an impressive display.
5. He decided to present from the information off of the computer. No, No No. This is not good. I'm not even sure what you mean. Perhaps something like this? -
He decided to present the information using his computer.
He decided to present information he obtained from his computer.
6. His keen interest in the topic is demonstrated in his taking notes during the presentation and posing(or asking either ) thought-provoking questions. If you are speaking of his habits, say 'presentations'.
You wrote pretty good sentences.
Best wishes, Clive