Main mods:
Hotseat (for narrative variation) RimOut: Legion Faction SK's Fallout Great Khans Bad Hygiene Communicable Diseases Hospitality Gastronomy ReGrowth - Wasteland (requires ReGrowth Core) ReGrowth - Mutated Animals Fallout Races Ghouls and Robots (Seperate mods) Vault Tec Handy things [O21] Fallout Armoury The Forge - NCR Armoury
If you don't understand how the parts work, what they do, how delicate the connectors are... Without any experience you can't know what not to do. Trying to build a PC, a lot can go wrong if you don't know what you're doing. That a lot of expensive parts that can be destroyed in a blink of an eye if you make a mistake.
You say all the parts fit only one way. Well, that depends on how clumsy or ignorant the builder is. Or both