たまに would mean occasionally/once in a while right?
how can we translate んだ in this context? or is it just an expression? if the translation is wrong, do tell me.
Text: たまにはなプレゼントをもらっていいと思うんだ。
Translation: I think it is okay to receive present once in a while
よろしくお願いします！
Yes たまに means "occasionally."
んだ at the end of the sentence is not related to たまに. This んだ is the colloquialism for のだ, which is often called explanatory no(da). In your sentence, んだ is not necessary but used for mild emphasis. Most of the time you don't have to translate this のだ explicitly.
By the way, the な after たまには is one of the masculine filler particles which do nothing semantically.
Text: たまにはなプレゼントをもらっていいと思うんだ。
Translation: I think it is okay to receive present once in a while
Yes. This translation is correct. You can also say it without "んだ".
たまにはプレゼントもらっていいと思う。
You use the first form when you talk to someone.
