Ransomware is a virus that, once it becomes active, starts to encrypt all your files on your computer's hard drive. Only at the expense of a large amount of money, you will find a key to recover your files from the ransomware criminal gang. If it takes a bit of it.
So-called trackers follow your browsing behavior from site to site. Of course, with the intention of making a digital profile of you, for example, destroying you with targeted ads. However, your entire browsing behavior can also be used for one thousand and one other less pleasant intentions.
If you are on vacation, you are likely to use a local hotspot for your internet needs. Consider, for example, the Wi-Fi network at the hotel or at the campsite. Or just hook up with the network of your local Starbucks or McDonalds.