I took my daughter to Spain when she was about 5 months old. The Yoyo stroller is tiny and easy to carry, can also fit in the cabin if you wanted to store it there. In regards to flying, I took some ready to drink milk bottles and gave her one on take off, she slept the whole journey and then woke during the landing. I also bought a sunshade extender for the stroller and a fan that attached to the stroller x
Baby City jogger is a much cheaper option than the yoyo but still amazing quality. £195 I just took it to Australia for 2 weeks with my 3 month old and it was amazing. Folds up so it goes as a carry on stroller.
I would appreciate tips for travelling, too, but from what I have read is that there should be as little as possible skin exposed to the sun, there are swimming suits with UV protection. A sun hat is a must. If you carry baby in a sling/carrier, that's considered as another layer of clothing, so consider this especially in really warm weather. Feed baby during landing and take off to make it more comfortable for them and prevent/reduce ear popping. If you're going to the beach, have a look at beach tents for babies. Of course, reapply every 2h baby friendly SPF.