Solana nft

am trying to avoid traditional method of buying nfts with wallet & instead wanting to buy it with code only and onchain. i understand the idea behind the solana transactions and its Instruction Format (CreatAccount,Memo...) but what i lack is the way to let the buyer & seller sing the transaction and confirm it therefore transferring the nft from Seller to my wallet (the buyer).

sorry for the confusion if there is any question or details i 'll happily provide it !


transactions docs :
https://docs.solana.com/developing/programming-model/transactions#instruction-format