I'm attending a wedding later in the month. It's my partners brother who is getting married and they're having a
very small celebration. They're getting married in a registry office and just having lunch afterwards with a group of ~20. I've been looking forward to this as it will make a freshing change to all the typical large weddings that we've been to.
However I've just found out through the grapevine that they plan to stop off at a park between the ceremony and the lunch to take photos. So naturally I asked (my partner, who heard from his mother) if they had decided to hire a photographer. But no... it turns out they'd like my partner, his Dad and myself to take the photos. In theory that's not a problem. We all have decent enough little cameras and would be taking our own photos even if there was a professional photographer. However given that my partner and his Dad will naturally be in a lot of the "family" shots, I'm kind of feeling the pressure

So I'm worried that:
1. My photos won't turn out great (e.g. could be poor weather/lighting conditions that I wouldn't know how to work around). I know I'm just being silly though - if the photos were that important to them, surely they would've hired a professional.
2. That I'll be left out of most of the "family" photos. I just don't want to feel like I'm on the sidelines and only there to take photos

It's a family event and I'd like to feel part of it. Before anyone suggests it, I don't own a tripod in order to take photos on a timer with everyone in them.
Please tell me I'm being silly and worrying over nothing

Has anyone else ever been in a similar position?