Now, let think of which exchanges you should choose to buy bitcoin.
- Centralized or decentralized exchange: Most of centralized exchanges ask for KYC, but there are non-KYC exchange like Binance (if you don't withdraw above 2 BTC in total per day). Most of decentralized exchanges don't ask for KYC, so you can use them. Nevertheless, it is worth to warn you that you have to secure your private keys yourself after creating accounts on decentralized exchanges. Losing private keys and account usernames, you will lose both your accounts & your bitcoin. It's certainly your faults, not exchanges.
- What you should do next after buying bitcoin on exchanges? Storing them there, nope.
Because exchanges can be hacked, you know that, right? So, you must withdraw your bitcoin to non-custodial wallets that you have full control (with wallet private key)
There are lots of advanced bitcoin wallets to choose, but which one you choose, you have to read and pratice backup and recover wallets from private keys/ seeds, before you withdraw your money from exchanges (centralized or decentralized, whatever) to your wallet.
Don't buy bitcoin on exchanges if you have not yet known how to install, backup, recover with bitcoin wallets.
Withdraw your bitcoin ASAP after buying it. It is more fitted to your intention, because you don't want to store your bitcoin on exchanges, don't want to trade, withdraw ASAP is perfect.
In fact, you must do the second step I mentioned first, because you have to prepare your wallets before buying bitcoin.
[General] Bitcoin Wallets - Which, what, why?
Choose your wallet
Newbies - Read before using exchanges or investing
Electrum wallet - Update safely and avoid phishing wallets?
There is another way if you don't want to buy bitcoin on exchanges, is buying bitcoin from high trusted users, whom run Escrow services in the forum. However, I don't suggest to do that, because you can easily buy bitcoin on exchanges.