If you wanna shop,then you can do that in a shopping mall nearest to you
But if you're looking to purchase bitcoins,you can do that via a recognized exchange,you can try googling about them, to get a more detailed description and how they work
Here are few examples:coinbase,Binance,coinbull,Luno,markets.com
You can so purchase bitcoins via decentralized exchanges,if you feel they'll be safer for you
DEX such as:IDEX,Wavesdex,openledger dex,Oasisdex etc..
https://www.bestbitcoinexchange.iohttps://bitcointalksearch.org/topic/general-how-to-earn-bitcoins-1629118You can also purchase bitcoins directly from an individual,without the use of an exchange,but while doing such, the seller must have an account on this forum, and must be a trustworthy member
Also the trade Must be conducted using a third party trusted escrow service,to umpire the transaction,and keep you safe incase something goes wrong,the trusted third party must be of high reputation in this forum, and have a plethora of positive trust rating,take note; trust isn't based on rank
https://bitcointalksearch.org/topic/recommended-bitcointalk-escrow-services-2439910 
