A step by step guide to share with no coiners, so you don't have to waste hours of your time.
Step 1:
Read the following document. In 15 minutes, it covers almost every topic relating to Bitcoin.

Bitcoin Basics
15 minute guide to go from a beginner to a self sovereign bitcoin holder.
Step 2:
Read the bitcoin whitepaper. The original document published by Satoshi Nakamoto in 2008.
https://bitcoin.org/bitcoin.pdf
Step 3:
Watch the videos in this YouTube playlist, in order is best. You can probably move onto step 4 after the first few videos. But be sure to keep watching, as there is a lot you can learn here, in around 24 hours of videos.
https://youtube.com/playlist?list=PL1D6Yv8tqcOJ_3OjzWrvf-XEBq0rys1nI
Step 4:
Purchase bitcoin from an exchange. Below are the best options imo based in the UK, each have different fees for purchases and withdrawals, and different ID verification levels known as kyc.

Relai – Buy Bitcoin Today!
Buy Bitcoin (BTC) with Credit Card or Bank Transfer - Relai App
All you need to get started is to download our award winning Relai app, complete a simple verification and start buying with as little as 50 CHF/EUR.
(1-2% buy fee, no kyc for small purchases, no withdrawal fee)

Peach Bitcoin Exchange - Buy and Sell Bitcoin Anonymously and Without KYC
Peach Bitcoin - Buy Bitcoin with gift card, no verification. Exchange peer to peer for anonymous transactions. Learn how to buy and sell Bitcoin pr...
(2% buy fee, no kyc, no withdrawal fee)
https://www.kraken.com/ (0.26% fee, need kyc, 0.0002 BTC withdrawal fee or free with lightning)

Nexo
Nexo: Your Wealth Platform for Digital Assets
Discover Nexo, the comprehensive platform that's driving the next generation of crypto wealth. Grow, trade, borrow and earn on your digital assets.
(0.2% fee, need kyc, 1 totally free withdrawal per month)

CoinCorner, Ltd.
Buy, sell, send, receive and store Bitcoin (BTC) | CoinCorner
Established in 2014 and trusted by over 350,000 people, CoinCorner is a trusted place to buy, sell, store and spend Bitcoin.
(1-5% fee depending amount, need kyc, no withdrawal fee)
Coinbase Advanced: Trading platform for sophisticated crypto traders
550+ crypto spot pairs with as low as 0.0% maker fees, up to 5.1% USDC rewards on your trading balance, TradingView charts, and more.
(0.6% fee, need kyc, withdrawal fee varies depending on network traffic)
Step 5:
Withdraw the bitcoin from your exchange account to a self custody wallet where you hold the keys, ideally a hardware cold wallet or your own node, otherwise a mobile hot wallet. Relai and Peach come with a mobile hot wallet. Below are some other wallet recommendations.
(mobile hot wallet, liquid network wallet, connect to hardware wallet)
This Website Has Been Seized
(mobile hot wallet, connect to hardware wallet, high privacy features)
(mobile hot wallet, lightning network wallet, lightning mobile node)

Blockstream: Bitcoin and digital asset infrastructure
Blockstream Jade: A powerful hardware wallet for securing your Bitcoin.
Traders. Hodlrs. Investors. Your Hardware wallet is here. Jade is the most advanced hardware wallet yet.
(hardware wallet, liquid network wallet, bitcoin miner)

COLDCARD - The Most Trusted and Secure Signing Device (a.k.a. Hardware Wallet)
COLDCARD Is The Most Trusted and Secure Bitcoin Signing Device (aka. Bitcoin Hardware Wallet)
(hardware wallet, extra security features)

BitBox | The easiest way to keep your coins safe
Swiss-made hardware and software for easy Bitcoin and cryptocurrency storage.
(hardware wallet)

Nunchuk
Nunchuk - Secure Your Bitcoin for Generations
The first Bitcoin inheritance solution designed to outlive the company that created it. Built on the most advanced multisig platform. Trust-minimiz...
(mobile hot wallet, connect to hardware wallet, multisignature)

Bitcoin Core
Bitcoin
Bitcoin
(official bitcoin node, best security of all, not for beginners)

Umbrel - Personal home cloud and OS for self-hosting
Bring the cloud to your home with umbrelOS - a beautiful home server OS for self-hosting, and Umbrel Home - a plug-and-play home server. Install Ne...
(unofficial bitcoin node, lots of extra features, highly secure)
Step 6:
Always keep learning, run your own bitcoin and lightning nodes, open lightning channels, start a NOSTR account.