These are indeed conditional statements and it follows this pattern:
(X は) Verb+たら, Y
If X, then Y.
夜だったらいます。
If it's at night, then I'll be (there, here, at home, etc. ; depends on the context of the conversation).
This sentence doesn't necessarily translate smoothly in English when translated directly, but this is the idea.
大きくなったら新聞きしゃになりたいとおもいます。
When I get grow up (literally: "get big" in the Japanese version), I want to become a newspaper reporter.
I hope this helps. Let me know if you need further help.