Not all exchange required to pass KYC or you need to input your personal information. You can still buy bitcoin and any altcoin without submitting any personal informantion because some exchange only required it if you gonna withdraw a huge amount of bitcoin like 100 bitcoin. But, in your case you already stated that you can't buy huge amount of bitcoin and altcoins so it's better to use an exchange than buying it to a certain person which is more risky than using an exchange.