How can i make a new app with flow ,where is my start point

⚙️ Flow SDKs Flow Go SDK
1

Messrs, i want make app just like NBA_TOP where should i start ,i had read candence, Flow Emulator, go sdk ,as a Back end ,where could make test env

2

now ,i want make a go api /create_acount

i follow the example create random seed an string len 32
then get the privateKey publicKey
then use templates.CreateAccount get a scrpit
c, err := client.New(“access.devnet.nodes.onflow.org:9000”, grpc.WithInsecure())
err = tx.SignEnvelope(payer, payerKey.Index, payerSigner)
NewUserAddress = accountCreatedEvent.Address()
finally address is 0000000000000000

Why the address is 0000000000000000
and i don`t konw which step mistake ,there is no panic happen
next is my code

func (this *MarketController) Create_uer() {
o := orm.NewOrmUsingDB(“default”) // 创建一个 Ormer
Name := this.GetString(“username”)
if Name != “” {

  User := new(models.User)
  User.Name = Name

// start make NFT relevant
///
ctx := context.Background()

  random_seed := beegoutils.Random_string()
  // 为账户生成一个新的私钥
  // 注意: 这只是一个例子, 请使用安全的方式随机生成种子
  seed := []byte(random_seed)
  //fmt.Println("seed",seed)
  privateKey, _ := crypto.GeneratePrivateKey(crypto.ECDSA_secp256k1, seed)
  encPrivateKey := privateKey.Encode()

  // 得到公钥
  publicKey := privateKey.PublicKey()

  // 从公钥中构建一个用户密钥
  accountKey := flow.NewAccountKey().
  	SetPublicKey(publicKey).
  	SetHashAlgo(crypto.SHA3_256). // SHA3_256 哈希算法生成的密钥对
  	SetWeight(flow.AccountKeyWeightThreshold) // 授予这个密钥签名权重

  //const rawPublicKey = "9cd98d436d111aab0718ab008a466d636a22ac3679d335b77e33ef7c52d9c8ce47cf5ad71ba38cedd336402aa62d5986dc224311383383c09125ec0636c0b042"
  //publicKey, err := crypto.DecodePublicKeyHex(crypto.ECDSA_P256, rawPublicKey)

  var address flow.Address
  // 生成一个帐户创建脚本
  // 这将创建一个帐户，该帐户只有一个公钥，没有代码
  script := templates.CreateAccount([]*flow.AccountKey{accountKey}, nil, address)

  // 连接到本地运行的模拟器
  c, err := client.New("access.devnet.nodes.onflow.org:9000", grpc.WithInsecure())
  if err != nil {
  	panic(">>>> failed to connect to emulator")
  }

  signer := crypto.NewInMemorySigner(privateKey, accountKey.HashAlgo)

  payerSigner := signer
  payer := flow.HexToAddress("0xfc98bbf96a3ef8c1")


  acc, err := c.GetAccount(ctx, payer)
  println( " address  >>> ",acc ,err )
  payerKey :=  acc.Keys[0]


  //(flow.Address, *flow.AccountKey, crypto.Signer)


  //payer, payerKey, payerSigner := examples.ServiceAccount(c)
  //fmt.Println("|",script,payer,payerKey,payerSigner)


  // 获取 上一个区块头
  //referenceBlockID := examples.GetReferenceBlockId(c)
  isSealed := true

  latestBlock, err := c.GetLatestBlock(ctx, isSealed)
  referenceBlockID := latestBlock.ID
  //script_value,_ := script.([]byte)
  tx := flow.NewTransaction().
  	SetScript(script.Script).
  	SetGasLimit(100).
  	SetProposalKey(payer, payerKey.Index, payerKey.SequenceNumber).
  	SetPayer(payer)

  // Sign the transaction with the service account, which already exists
  // All new accounts must be created by an existing account

  // 业务签名
  fmt.Println("payerKey",payerKey,payerKey.Index)
  fmt.Println("payerKey.Index",payerKey.Index)
  fmt.Println("payerSigner",payerSigner)

  err = tx.SignEnvelope(payer, payerKey.Index, payerSigner)
  if err != nil {
  	panic("failed to sign transaction")
  }
  tx.SetReferenceBlockID(referenceBlockID)

  err = c.SendTransaction(ctx, *tx)
  if err != nil {
  	fmt.Println("panic %v", err)
  	panic("failed to send transaction ")
  }

  result, err := c.GetTransactionResult(ctx, tx.ID())
  if err != nil {
  	panic("failed to get transaction result")
  }
  // 获取地址
  var myAddress flow.Address
  fmt.Println("result", result)

  for _, event := range result.Events {
  	if event.Type == flow.EventAccountCreated {
  		accountCreatedEvent := flow.AccountCreatedEvent(event)
  		myAddress = accountCreatedEvent.Address()
  	}
  }

  fmt.Println("Account created with address:", myAddress.Hex(), myAddress)

  // 准备新增用户所需数据
  User.Address = fmt.Sprintf("%v", myAddress)
  User.PrivateKey = fmt.Sprintf("%v", privateKey)
  User.PublicKey = fmt.Sprintf("%v", publicKey)
  User.AccountKey = fmt.Sprintf("%v", accountKey)
  User.EncprivateKey = fmt.Sprintf("%v", encPrivateKey)
  fmt.Println("PrivateKey", privateKey, "publicKey", publicKey,"seed",seed,"encPrivateKey",encPrivateKey,)
  // 先 创建钱包 再创建用户

  wallet := new(models.Wallet)
  wallet.Balance = 100
  w_id, w_err := o.Insert(wallet)
  User.Wallet = wallet
  id, err := o.Insert(User)

  //返回插入成功消息
  if err == nil && w_err == nil {
  	this.Data["json"] = map[string]interface{}{
  		"code": 200, "message": "ok", "id": id, "wallet_id": w_id,
  	}
  	this.ServeJSON()
  } else {
  	this.Data["json"] = map[string]interface{}{
  		"code": 200, "message": "fails", "id": id, "res": " inseart mysql fails %v, $v " + fmt.Sprintf("", err, ) + fmt.Sprintf("", w_err),
  	}
  	this.ServeJSON()
  }

} else {
this.Data[“json”] = map[string]interface{}{
“code”: 200, “message”: “fails”, “resule”: “miss username parmas”,
}
this.ServeJSON()
}

}

3

What error are you getting?