I've taken 3 trips to Europe recently (not a humble brag) and people are wearing whatever they want. Within reason of course, you're not seeing halter tops or hot pants (from either gender). Just watch a few of those "a walking tour of ..." insert city name here videos and you'll see. Every city has multiple outlets of Zara and H&M and sometimes Benneton, so if they sell it you'll see it being worn. Everyone young and old and local and tourist wears jeans, so it's not a major concern unless you're planning an upscale trip in which case dark colored chino type pants and a sweater will work. I'm old enough to remember feeling somewhat naked without a sport coat, believe me those days are ancient history. The only reason to do that now is for the pockets.
The one suggestion I would make is lay off the clothing that is covered in logos or has very large logos. If that was "in" for a time, it's "out" now. Apparently this is partly due to the show "Succession" where people noticed that the rich were not flaunting their richness with outrageous branding, even though their outfits sometimes cost more than small cars.
Also go easy on the branded baseball caps, they are not nearly as prevalent as over here. I found a logoless cap at H&M that did the trick for me.