Wow, you're too kind!!
I've actually only been sewing/ taking pictures for a year and a half (in the little amount of free time I have opposite school), so I don't know very much DX but I'm willing to share all of my knowledge with you!
I wouldn't say you NEED a partner, but it's nice to have one! My sister took the pictures of me as Rapunzel, and the Lin/Ren photos were by a friend. So really, you could let anyone take pictures of your cosplay! You could also plan your photoshoots, or just do them on the fly. The Lin/Ren photos were taken during a convention when we were taking a break and spending some time in our hotel room and in the hallway outside our room. Some of the Rapunzel photos were taken in my backyard when I got back from a convention, and some of them were taken during the convention at a Disney photo shoot event. All of my WIP photos were taken with my phone in my room. For the cameras used, they varied in quality, so I think any camera would work fine, especially since digital cameras keep getting better and cheaper every year! Only three of my photos are edited: Len, Rin+Len, and Rapunzel (the close-up of my face). I barely know anything about editing photos, but I use photoshop (the old version that they released for free) to make my skin smoother, eyes slightly wider, and to blur the background. Occasionally I'll mess with the colors or saturation to make it seem like I added "effects". I'm sure if you looked up some simple photoshop tutorials, you could figure it out! And if you don't have photoshop yet, download the old free one and just try experimenting with different tools.
If there's anything else you'd like to know, don't hesitate to ask! :3