First of all, before you read this, I would like to say that this is a quite outdated method for creating a Bitcoin wallet and it is better to use a mnemonic phrase if at all possible.If it is done properly, that is in an offline environment, no internet connectivity, no USB devices attached or any Bluetooth connections or the like, then the resulting wallet is very secure. In fact you are more likely to lose your wallet than for someone to hack it.
In this guide we will be using BitAddress.org. It is one of the oldest programs available for creating a Bitcoin address. In fact, creating a BitAddress wallet is more secure now than it was back then, when
many libraries had serious vulnerabilities.Let's get started.
Warning: Do not send any bitcoins to the addresses in the picture, or you will be robbed!Step number one is to type "bitaddress.org" in your browser. I always recommend you do this instead of searching for it on google to avoid any phishing sites.
Now you are going to move the mouse around in random directions and bang on your keyboard and there will be green dots appearing like this:

Step number two is to keep doing this until the progress reaches 100%.
Tip: moving the mouse around like a madman is much faster.
Step number three is to SAVE THE DETAILS OF YOUR WALLET. THIS IS VERY IMPORTANT. Do not close the browser or go to another page until you do this, otherwise you will lose your wallet forever. Also do not send any bitcoins to the wallet until you have written down the private key completely.
Never save private keys on an electronic device.
In a similar way, you can create a paper wallet. A paper wallet is a wallet that contains a single private key and address, but it is shaped like a piece of paper with QR codes on it and you can print it. It is not much different from the single-address wallet, and if you ask me its a bit more dangerous than the above method since you don't want thieves or other people to see a giant bitcoin logo on your private key. Nevertheless you can also create a paper wallet on Bitaddress.org by following a similar process.