its an operating system issue your operating system is not giving you permission to change files you have to find how to give yourself permission to edit/delete files where you have installed the mods
not to mention that the starting vault is quite brittle --- exit vault before adding mods. Some people even suggest playing vanilla until after killing the deathclaw in Concord then saving there for future gaming
did you read the thread about NMM and how to enable mods https://forums.nexusmods.com/index.php?/topic/3468450-link-to-nexus-wiki-how-to-use-nmm-for-fo4-mods/