I hope that the lens you acquired is a wide angle as that is what I have found important for backpacking. I usually only take one lens, a 16-70mm, for backpacking. I do consider also taking the 35mm f1.8 for its light weight and low-light capability.

If you are getting back into the photography hobby, I would highly recommend acquiring Lightroom for organizing and processing. It can do some great things that were once only within the purview of Photoshop. And you can get both for $10 per month on an annual subscription. If you are shooting RAW, then you definitely need some type of processing software.