Word order/sentence structure.

Hi all.

Just wondering if both "ともだちにきょかしょをかりました" and "きょかしょをともだちにかりました" are valid sentences and that they mean the same thing.

My understanding of Japanese sentence structure is that sentences generally start with the topic (in this case would be わたしは but is excluded here as it's implied), ends with a verb (in this case かりました) and in the between are various noun-particle sequences which are flexible in their arrangement.

Please let me know if I'm off about anything. Thanks

Yes, those two sentences are both correct except a typo きょうかしょ, and your understanding about the word order is basically correct.