Answer:
He always thought, "I must find a good friend."
Step-by-step explanation:
I also capitalized it, without capitalization and only punctuation it'd look like: "he always thought, i must find a good friend." You always capitalize your I and always have a comma when you're referring to someone saying, thinking, ect. You're end point ( or " . ") must always go before the parentheses. Hope this was helpful!