As per my advice for buying a new mobile phone
If buy through online shopping, see all terms and condition written through seller side, means it should not be refurbished or used for some time.
If buy through any shop then always check the sticker before open mobile box.
Specifications : Try to buy a mobile firstly check which company makes it and the version of that brand mobile.
Secondly, after opening that box try all accessories which are written on that box and in the box are same. Because many of the small dcale mobile seller open a mobile box with hot air gun. So that’s why check all accessories carefully. Thanks