Appropriate Conversations

So, I have to attend a wedding in July. It's the first wedding on my Mom's side of the family. My brother is out of the country and won't make it. So the oldest male role falls on me(patriarchal society and their BS). I want to make a good impression on the guests but I just don't think I can make decent conversation with them.
Generic advice like "Just Be Yourself" just won't cut it because a normal conversation for me revolves around drugs, drinks and dames. I don't think that will sit too well with the highly-conservative Christian guests.
I'm not trying to make them think I'm the next big thing, I just don't want to come off the wrong way and screw up some potential networking opportunities.

What do Normal people talk about? And if you were in this situation, how would you go about working on yourself given a duration of 30 days?

 

Weird thing is IDK. Most of them will know me but I have no effing clue who most of the guests are. Sports is not really a big thing among that crowd. People my age maybe but not for the older relatives. Besides, the ones who do all watch cricket(I'm assuming it's cricket season now?) and I hate the sport. The older women will just be like
I'm assuming that majority of the crowd is going to be around the age of 35-40

Small talk seemed easier when I was younger and more laid back. People would ask me how my studies and stuff were going and I'll just tell them I don't care about it and just go off on some nonsense rant. I used to be known for that actually. Now however being responsible is a big thing, and I feel like I'm still a happy-go-lucky kid which would definitely give off the wrong vibes.
Thanks for the links I've seen a few but most of those just wont come up in a normal fluid conversation.


Assuming that there are about 250 guests and I spend about 2 minutes, that'd be around 500 minutes(8 hours). I'll be chilling with my family for the ceremony and since I'm part of the family, I'll be there till most of the guests have left. Factoring in that many of them will be grouped into 3 or 4 each that brings it down to around 2-3 hours during the reception.
Most people, from what I've noticed, just sit and talk about how they're related to each other or some other nonsense about their life. I've got nothing going on for me at the moment so I'm kinda stuck.

 

Well sadly I'm no stand up comedian. I can make people talk about themselves for hours but becoming quick witted is something I definitely have to work on

 

I can make people talk for hours about themselves. But I hate talking about myself so I just get a feeling that other people feel the same way too. And escaping a conversation is a breeze. I've been running away from stuff all my life
People love talking about themselves, true. But when the ball is rolled back to my court I just can't seem to go on and on about myself, at least not with a mature and civilized crowd.