It depends entirely what you intend to do. I would recommend an Apple MacBook Pro unless you really need to work with another operating system.
Start with Operating Systems. They are the face of the hardware.
Apple's OS will not (legally) run on generic Intel Laptops. Linux will. Windows is the most common.
Apple was designed to be easy to use by creatives and non-techies. The operating system is robust and has lots of really nice features including auto backup. If you are a developer who needs to work in Windows or Linux you can run these systems in a virtual machine and get a lot of programming languages free. It is pretty secure but you still need to be careful. If all you want is the normal Office functions you can get these using free software. And save them in Microsoft format. Note that some hardware ( some brands of printers and scanners) may not work with Apple or Linux.
Windows is the most common system. It was intended for the business user. It has a lot of security holes and is in many ways less pleasant then Apple to use. There are very few features Windows has that I miss on a MAC
Linux is for the techie. You cannot use Linux without some technical knowledge. In fact normally you need some technical knowledge just to install it. However it gives you full control
Now to Hardware. Apple is the most expensive. Windows and Linux cost the same but you have to install Linux. In terms of quality Apple beats a standard PC, and should last the 10 years guaranteed chip life. The laptops are heavy, but if you can tolerate a small screen then the MacBook Air is light and thin.
As stated by Rolly, you have to be careful about Internet access. I usually find Hotels etc give good Wi Fi free or at reasonable rates (except the most expensive ones where it is expensive). An internet stick works well ans buying a local sim card for access can cut the cost dramatically ( In Germany flat rate €25 per month)
Applications: For most people the minimum is a word processor, a web browser and skypr or similar. These are available for all Operating systems.
Most Laptops have very similar specifications, but
The more RAM the better but paying 200 more for an extra gigabyte ram is not sensible.
The bigger the screen the better but also the heavier the computer.
Try the machine before buying. The trackpad may be very stiff, the screen may not be quite right for your eyes.