Cheesus
Try getting into biking. I burn 1500-2000 calories (I’m not a small dude) in like 2 hours of road cycling. It’s relatively easy on the body compared to running as a bonus.
This is all excellent advice, especially regarding France. Where I live, which is only 20 minutes from Geneva, you’d be lucky to find anyone outside larger towns who can speak English confidentially. And forget about it if you have an accent other than very standard British or American.
Europeans in general appreciate the small things in life much more than Americans. Like everyone has already said, try and relax and take it all in, rather than rush from place to place trying to cram as much as possible into your trip. Have that second glass of wine, or that dessert that looks amazing, or even that afternoon nap after a long lunch. Trust me, you remember those moments just as fondly as the big ones.
Lyon is pretty great. Depending on the vibe you’re going for, Marseille is also pretty awesome. I’d avoid it in the middle of the summer, but shoulder season down south is amazing. The weather is great, the people are friendly (if you avoid the worst parts of town, like anywhere) and the food is a nice mix of traditional French and Mediterranean cuisine. And make sure to get a flight of Ricard.