Advice for amateur asked to photograph at friend's wedding?

Hi everyone!I have been dabbling in amateur photography for a little more than a decade, just as an occasional hobby. I don't have much equipment, and I'm still using entry-level camera, my (by now old) Nikon d5200. I have a telezoom lens, a fish-eye lens and the standard lens, as well as a reflector disc for portraits. I shoot in raw-format, do finishing in lightroom and the occasional use of photoshop if needed.Recently I got an invitation to an old friend's wedding in the mail, and the wedding is in July. It will be held in a relatively countryside location. When asking more details about the wedding, she asked me if I would be interested in not just casually documenting their big day, but if I would take their wedding photographs as well.She offered to pay, but I don't feel comfortable taking money for my work seeing as I'm just an amateur and this is an old friend. We were something like best friends in high school, before we went our separate ways for college. Of course, in my opinion, being asked to do this is a great honor. I'm happy that they think my photos are good enough that they would like me to document their big day.I'm thinking that the shoot, editing and print could be my wedding gift to them, since as a student my economy is pretty tight and I already have to spend $300 in transport to get there.However, it also makes me beyond nervous. I have photographed at a wedding once before, and that was just casual documentation when I was but an enthusiastic teenager without any experience.The wedding is in less than two months.I won't have a chance to see the location for the wedding photos until the day before the ceremony. All I know is that it's in a summer garden. The session is planned to be done in 90 minutes between the actual ceremony and the wedding reception, so I won't have much leeway when it comes to time.I would take any advice right now on how to prepare, plan and perhaps even whether I should consider getting more equipment. Any helpful sites, tutorials, inspirational examples that you would know of are welcomed! Please calm my nervous self! T_T via /r/photography https://ift.tt/2GJaUU2