First steps: Start Julia in a certain folder in VSCode

In WARNING: using x.x in module Main conflicts with an existing identifier my problem occurs. Basically, the problem seems to be, that I cnt really operate in Julia and I try to fix that. I just want any Code from Github with everythin included, e.g. Manifest, Projekt, a src-folder and maybe some other folders with example programs. I then want to run that without havin problems and I dont get there. Maybe its because the Code is wrong, but I dont think that. [PetrKryslUCSD] just send me an example and I will try that first.
Sorry for asking so basic things!