Welcome to H,S,& R.
Look at the top of the column and find the sticky entitled All Setup Questions...
Read through the first couple of posts. It will answer most of your questions. Note that there will be some data that needs to be collected: String heights at the twelfth and last frets and relief, both on the bass and treble sides; and later data on the nut. The more data you provide, the easier it is to diagnose any problems.
If the neck is not installed on a body and under the load of the strings, there is little to go on. Test the truss rod to make sure it is working. If it is, install it and post your findings here. Someone will help you.