Install anchor from this installation guide https://www.anchor-lang.com/docs/installation

write you smart contract in /anchor/programs to build use command anchor build

for testing you can use local solana validator to start it type solana-test-validator and go to explorer.solana.com and select the net to Custom RPC url and past ethe localhost url now we can watch all the transactions of it there

for testing we use anchor build
install it using npm i anchor-bankrun
to run the tests we can use anchor test --skip-local-validator --skip-deploy