Congrats on your new Evie!
I have 2 evies that's 10+years old. It went through rain/snow/humid heat, and its still looks good as new. My SA calls my evies my "rain bag"

What I do is use Saphir Nappa Conditioner and Saphir Canadien Garments (neutral color is the best). The Canadien is specifically for jackets and bags so that the polish won't rub off onto your clothes (use brush to polish it off (the bumps on Clemence can get polish stuck on it)). The polish acts as a barrier between water and leather, and I do this once or twice a year. There are other reputable high grade companies if you can't find Saphir that Docride recommends. For the strap, I use scotch guard to waterproof, and keep it from fuzzing up, which normally happens after several years. I suggest using bag liner to keep it in shape, as it will stretch out over time if you overstuff it HTH!
