So i just got fallout 4 for the week and i started to play the game before updating it, and now i was just wondering (cause i keep hearing people say in youtube videos) are all workbenches junk section all connected? I keep "transferring" all my junk into the first settlement you start off with and none of my other settlements have the same supply. I literally have to grab all the resources i need and fast travel to the settlement i need to build on, please help with this question that is making me think about restarting my whole character.

you have to have the local leader perk for this

And you have to assign a settler to open a trade route to another settlement. Only settlements linked by Provisioners (via the trade routes) share junk/aid from the workbenches.