Agree with WrightSocks recommend - get their dual layer anti-blister socks. But skip the duct tape and be proactive from the start and buy some BodyGlide which is what runners use to prevent blisters, hot spots and chafing. Rub it all over your feet (including toes), wear the WrightSocks and a decent pair of shoes. What brand is entirely dependent on your feet so try on a lot of brands to figure out works best for you. My Go To brands for walking that work well on cobblestone, brick or uneven but easy walking trails tend to rotate between Merrell, Keen, Taos, Clarks, Abeo, Doc Martens and a couple pair of suede Dansko I managed to find that weren't ugly like the shoes they manufacture for medical personnel or chefs. All of them are great for being on my feet for extended periods of time.
I have several pairs of Allbirds. While they are super comfortable and keep my feet warm (or cool, depending on the season), they aren't good primary shoes for traveling as they don't have a whole lot of arch support or padding (though you can supplement them with some gel insoles from the drug store). My Allbirds Loungers are made from merino wool, so they will get wet if I get caught in a heavy rainstorm but they hold up fine in light rain. Still, I brought my Allbirds on my last trip to Europe as an additional shoe. I wore them to fly to/from Europe because they are really easy to slip on and off at the airport or on board the plane. They also look a little nicer than a sneaker, so I'll swap out my day shoe with the Allbirds Loungers when it's time to go out for drinks or dinner and I'm not going to be walking more than a mile or two. Because the merino wool stretches, they give my feet a break when they are tired or a little swollen at the end of the day.
To fly, I won't wear jeans for that long in cramped space. I wear a non-shlumpy loose knit pant from Talbots or J. Jill (not leggings) which have a flat comfortable waistband - no zippers or anything jabbing into me. I do pack some leggings in my suitcase, but I just don't like to wear anything super clingy when I'm going to be in a coach class seat for more than a couple hours.