Their are lot's of exchange which you can buy bitcoin your bitcoin but if you are using a centralized exchange, your funds can be freeze if you go against their rules, and if you want to use reputable exchange like binance and kucoin you will have to complete your kyc before you can access their P2P, before you can even trade on binance you have to submit your kyc, why you can trade on KuCoin without kyc but if you want to access their P2P you have to submit kyc and you will need to use their P2P service to convert your fiat into usdt.
@o_e_l_e_o listed some exchange which you can use their P2P services even without submitting your identity to them but I haven't tried it before and I don't know if they are allowed in your country.