Hi @weilueluo 
Can you expand a little on what the 2 requests are doing? Are they 2 independent API calls that are creating 2 different resources? If so, then a typical Terraform provider would separate the 2 API calls into 2 different resource create functions.
In terms of polling to wait for state, usually the create function would be responsible for waiting/polling to determine whether the resource was successfully created or not. This is described in this comment. So in the case you describe you would need to implement polling.