As you know, in English the structure "be going to" is used when you you have plans or made a prior decision so in Persian there could be some options. 1. من قصد دارم (میخواهم) در مورد ( درباره) پدرم به شما بگم (بگویم). Which translates as "I have the intention to tell you about my dad" in Persian when you want to talk about your plans, intentions, goals, you gotta use the subjunctive form of a verb, a verb with the prefix ب, as in بگویم. 2. من در مورد (درباره) پدرم به شما خواهم گفت. I will tell you about my dad. 3. من در مورد (درباره) پدرم به شما میگم (می‌گویم). I'm telling you about my dad. Like the present continuous in English you can use this structure to talk about an action which is going to happen in the near future. I hope this helps! 😊

من می‌خواهم راجع به (درباره) پدرم به شما بگویم.