To add: what the heck should we do with the iron trellis

Congrats! I have a brick midcentury ranch and could talk for days about them. While I'm a huge fan of authenticity in architecture and material choices in the home (i.e., I won't be getting rid of my blue and peach bathrooms, I love the Formica in my kitchen, and the paneling in my dining room isn't going anywhere!), I think that landscaping is one area where midcentury design typically fell flat. Most homes of that time had boring, low-maintenance "mustache" type shrubs all around as foundation plantings, a wide expanse of lawn, and not a whole lot else. But what I do like is Japanese style landscaping as well as more modern plants you can get with xeriscaping. I'm uncertain of what zone you're in (and I'm in Chicago, so I probably won't be able to give meaningful recommendations there!). I would look at more modern style landscaping to find ideas that are harmonious with the sparer lines of your home.

The iron trellis is period authentic for modest suburban ranches, but proportionally can look a bit underwhelming (though from what I can see, I like yours!). I don't think it would be a great tragedy to get rid of it, but perhaps try painting it once you've made your other choices and see how you like the look. I'm decidedly not a fan of trendy black windows on mid century homes, but depending on the style, they could work. I'm not sure what "picture frame windows" are, but if they're divided lite style, they're not the right fit for this house. Too traditional. The current double hung window style is the best fit for your home.

Please check out the website retrorenovation.com for a wealth of information on mid century homes and inspiration. My unsolicited advice is to take your time and don't get rid of anything original that's in good shape without giving it a chance first.