The fastest and easiest way to buy and store Bitcoin and other Cryptocurrencies in the UK is Coinbase https://www.coinbase.com. At Coinbase you can buy and sell Bitcoin, Ethereum, and Litecoin. They also have an online wallet so that you can keep your Cryptos safe.
You will need to connect your bank account and undergo a security check, this is to comply with anti money laundering laws. Coinbase is based in the USA but they have options to pay in Pounds, Euro’s or Dollars.
Check out Coinbase here: https://www.coinbase.com
The second best way to buy Cryptocurrency in the UK is Bittylicious https://bittylicious.com. At Bittylicious you have a lot more options to buy other Cryptos including Bitcoins, Belacoins, Blackcoins, CryptoCarbon, Dash, Dogecoins, Ether, Feathercoins, Litecoins, MonetaryUnits, Peercoins, Stratis, Syscoins and Vertcoins.
Bittylicious do not have an online wallet so you will need to find your own. We can recommend this online wallet – Exodus Wallet https://www.exodus.io
Or the most secure wallet is a hardware wallet – Ledger Wallet https://www.ledgerwallet.com