To me this sounds odd, but it depends on the context. I would say: He gets into trouble sometimes, but it’s not out of the ordinary for someone his age.

If you said this to me, I would understand you fully, however it doesn't sound natural. You're very close though! We can simplify the sentence in order to sound more natural. Personally, I would say: "He got into trouble sometimes, *but no more than* someone else his age." Keep up the great work, Andrew

No, and I cannot offer a correction because I cannot tell what you are trying to say.

He sometimes got into trouble, but nothing too out of the ordinary for someone of his age.