Yeah so..

[Drazja 0]

Suemary says it preaty much i know the DL'ed files go into the plugins.. then what do i just zone and the stuff wll pop up on its own in game or what? Is there mre to it or that it?  Oh yeah i guess I should introduce myself so ill keep it short.

[Muck308 55]

Welcome to Simtropolis, Drazja.

It all depends. Some of the building you download will have ploppable versions (meaning you can select them from the landmark menu and place them where you please.) and growable versions. Some just ploppable, and some just growable. You can tell by what files you install. The readme files usuallly tip you off as well. Or even the description before you download will reveal such information.

Anyway, when you install a building note what files come with it. If you see separate files with things like "GROW" or "LANDMARK VERSION" you will know there are different versions of that building.

[Duke87 1,070]

^^^ploppable things won't necessarily be in the landmark menu. If, for instance, you downloaded a custom school, it will likely be found in the menu with other schools.

But yeah, non-civic structures should be under landmarks, and if they're not there, then they grow out of zones. And if the building isn't showing up, that doesn't mean it isn't growable. There may not be sufficient demand for buildings of its type. You may not have the proper building set active. Or maybe, when zoning, no lots have been laid out of the right size. A 4×3 lot won't grow out of a zone of 2×3 lots. 

There are a couple of keys you can press while zoning to change the lot layouts... though, I forget what they are. It's been a few years.

[Drazja 0]

thanks gents, so it all depends what I'm looking for ty again