Here are some trusty sites and how to buy bitcoin or other cryptocurrencies:
https://www.coinbase.com Founded on 2012 and based in USA with 20million+ users and more than 150 billion traded.Use the certain link so we can both get $10 free bitcoin when you do a purchase of at least 100$.
https://cex.io Established in 2013 and based in UK with more than half a million users.
https://localbitcoins.com near of 1million users and founded back in 2012.This is a peer to peer marketplace so deal only with sellers that have good rating.In that kind of marketplace more privacy is possible but also bitcoin is more expensive .
https://paxful.com is the exact same concept like localbitcoins so only deal with sellers that have good ratings.
What you might need to buy bitcoin in that sites or others that are not included in the list:
1.)Your real name
3.)A smartphone that you own.
4.)Official ID or Passport (you might need to take a photo of document and upload)
5.)Bank or debit card details (only 3d secure type of cards are accepted – if you receive an one-time password on your phone or on email when you do online purchases then your card is 3d secure ) .Don’t worry use localbitcoins.com or paxful if you don’t want to take advantage of these types of payments.
6.)Selfie of you holding ID or passport (not always needed)
7.)Utility or Bank Statement that proves your address (This is rarely needed but just be prepared)
8.)Google Authenticator app (Not always)