Before buying a laptop one should decide his/her budget.
Then during buying laptop look for processor’s speed and generation, RAM configuration
Then if you are gaming person do check the graphic processor.
The screen resolution also matters for a good laptop.
If you prefer Nvidia GPU then look for 1000 series and if you prefer AMD look for 500 series of graphic chips.
Check that laptop supports latest M.2 SDD slot.
The weight should be light within 1.5 kg.
Or maximum 2 kg as per conveneince in travelling.
If you keep these aspects in mind you can buy a really good laptop.