Your problem with NONMEM is that you don’t grok NM-TRAN
When you first sit down with NONMEM1, it can appear considerably arcane. The “Zen” of NONMEM is that you’re speaking a language called NM-TRAN2; and you need to grok3 NM-TRAN. When you are writing a “model” in NONMEM, you are writing it in the language of NM-TRAN. The document you are writing in is a text file called a control stream, control file, or model file; it tells NONMEM what to do.