To buy Bitcoin from a member on this forum, you can ooenba thread on Currency exchange. Your account is new and not yet reputed, you will need to use an escrow service on this forum, there are some reputed escrow service providers which are reputed members on this forum, you can make use of them.

Recommended bitcointalk escrow services

If you are privacy conscious, you can make use of https://bisq.network, https://hodlhodl.com or Localcryptos. They are the best for privacy as they are decentralized.

If you are considering fee, you can make use of Binance that require zero fee for p2p trading, but you will need to provide kyc which will surely lead to privacy invasion.