Although OP, this isn’t how it’s done. You don’t need to shout out to the forum or everyone because you want to buy few fractions of Bitcoin.
That’s what the exchanges could help you archive. I see your under 18years of age from previous comments but, you don’t need age to own a non custodian wallet neither do all exchanges requires you of a KYC.
You might use a non KYC wallet to archive this buy and have it sent to your non custodian wallet. Then you can border about security or keeping your seed phrase safe/secret.