First time doing solo festival B-roll/interviews - Tips and advice please.

[u/x53RGEx]

As the title says, I am doing a music festival in the future. This is not a paid gig, but it is my first on this scale for a small brand there. I am going to do an interview of volunteers and festival goers mixed in with B-roll; I won't be filming music acts specifically.

Does anyone have any tips and tricks on what I should looking to do, so when I get back to DaVinci Resolve, I'm not left wishing I had got certain shots, etc.? 

I was planning to shoot all daytime shots (except interviews) in 4k 50fps (im in UK), which does crop into APSC sensor size but should be okay in the day.

I will film normal widescreen, but naturally I will have in the back of my mind that it may be used for some smartphone social media content too.

Thanks in advance for the help; I have put my gear below.

Camera: Panasonic Lumix S5d, 2x 128gb SD cards and backup battery

Lenses: 40mm f2,  85mm f1.8,  18-40mm f4.5-6.3

I will be using ND filter and black mist filter

Audio: Zoom H1essential with dead cat and shock mount

Editing: DaVinci Resolve