It's the first that.

All of your suggestions are OK and have the same meaning.

#2.

matthew1622 Can I say "it's the first time for me to watch this film"? Or should I say "it's the first time that I have watched this film"? Or can I say "it's my first time to watch this film"?

I'd say

This is the first time I've watched this film.

CJ

As you can see, matthew, native speakers have different ideas on this. My personal opinion is that you will hear all of them. I think I'd use CJ's version, but I am not saying that the others are unnatural.

CliveThis is the first time I've seen this.

I have absolutely no objection to 'seen' instead of 'watched'. I almost gave that as an alternate version.

CJ

AlpheccaStarsAll of your suggestions are OK and have the same meaning.

Thank you so much, AlpheccaStars.

CliveWell, if we want to be more colloquial, I'd say eg This is the first time I've seen this.eg I haven't seen this before. <<<<<<<<<<<<< A movie/film will be assumed from the context. (if there is a context).Clive

Thank you so much Clive. This was not the first time that you'd answered my questions and all of your answer

CalifJim matthew1622 Can I say "it's the first time for me to watch this film"? Or should I say "it's the first time that I have watched this film"? Or can I say "it's my first time to watch this film"?I'd sayThis is the first time I've watched this film.CJ

Thank you so much CJ. This was not your first time to answer my question and all of your answers, usually

fivejedjonAs you can see, matthew, native speakers have different ideas on this. My personal opinion is that you will hear all of them. I think I'd use CJ's version, but I am not saying that the others are unnatural.

Thank you so much fivejedjon. This was not the first time for you to answer my question and all your detailed answers helped me a lot. Thank you a