Before you buy, learn some basic knowledge of Bitcoin,

I would recommend you a website that has very detailed Bitcoin information (even from novice knowledge to complex technology)

GETTING STARTED WITH BITCOIN

I saved this website in bitcointalk, but I forgot who shared it，Thanks again to the original sharer

There is also a very detailed purchase method, just select your country, the website will list the method of buying btc

BUYING & EARNING BITCOIN